Is there a way to calibrate and update a fixtures FPE without having the fixtures position/orientation change in A3D

I might be misunderstanding your questions, but we are getting XYZ  data based on the manufacturer's report of Pan and Tilt ranges as translated proportional to DMX values and where in Augment3d you are saying the geographical placement is of the fixture in relation to 0/0/0. If that calculation gets offset over time without physically moving the fixture that to me means that the resolution is replacing belts or recalibrating the fixture.

Recalculating DMX P/T range is fairly complex in the field but here is a walk through. I would think this is a fruitless effort if a motor belt is skipping.
support.etcconnect.com/.../Troubleshooting_Fixtures_with_Physically_Different_Movement_than_Visualized_Movement

Yes I think there might be some degree of misunderstanding. The article you linked to correcting pan and tilt ranges is not what I am looking for.

As you know moving lights are moved by gears and belts, in order for gears to turn there has to be enough gap in between the teeth of the gears to move, if they were a perfect fit they would be firmly locked in place. However this means when reversing the direction of the gears, there is an amount of travel for the leading gear before it catches the following gear, this is called backlash. It is an extremely tiny amount, but it compounds on itself each time the gears reverse direction. It is my understanding that a combination of this backlash and imperfect homing/calibration on power-up of moving lights is what causes all moving lights to not precisely hit the same exact point on the stage day to day. This happens with all moving lights by every manufacturer due to the nature of gears.

Traditionally before A3D, we combat this with reference Presets, using known points on the stage we can focus our moving lights as tightly and accurately as possible. Then each day, or after each power cycle, we put our moving lights in their reference Presets, and make note of if they hit their mark as accurately as we need them to.

For example say I have a spike mark on stage at 0'/5'/0' for my reference Preset point. If after first focusing all my lights to that point and recording it I might come in a few days later, and notice Channel 8 is -1degree Pan off of 0'/5'/0'. If we know the fixture has not been physically moved, we know that for all our Presets and Focus Palettes in the show Channel 8 will be off by -1degree Pan. We can then in Blind select all our Presets or Focus Palettes and do "Ch.8 Pan + 01 Enter", and this will correctly update all of our Presets so they all go precisely where they should. Macros can of course make this a much faster process, but the steps remain the same.

To expand on our example let's say I also have 4 FPE points at the corners of our stage recorded, and on day 1 I used those points to Recalculate the A3D fixture positions so A3D and reality match. I can use XYZ data and type 0'/5'/0', and Ch.8 would precisely hit that mark. Now it's a few days later, and as before Ch.8 is -1degree Pan off of 0'/5'/0', and we know the fixture has not been physically moved. I can update our Presets recorded with Pan/Tilt data as we did before to correct for this, and all our recorded Presets will play back exactly as we want. However now if I try to use XYZ position to send Ch.8 0'/5'/0', it will still be -1degree Pan off of that point in space, despite the A3D model showing it hitting that point precisely. 

I could correct and update the focus of my 4 FPE points, Recalculate, and then Ch.8 should be able to precisely hit 0'/5'/0' when asked to. But as I said, doing this will change Ch.8's position or orientation in A3D, even though the actual position and orientation of the physical fixture has not changed.

I would like to be able update my FPE points, so A3D understands what Pan/Tilt values will correspond to a given X/Y/Z point, without having the fixture's A3D position and orientation changed.

Does that clarify for you what I'm talking about?

Yes I think there might be some degree of misunderstanding. The article you linked to correcting pan and tilt ranges is not what I am looking for.

As you know moving lights are moved by gears and belts, in order for gears to turn there has to be enough gap in between the teeth of the gears to move, if they were a perfect fit they would be firmly locked in place. However this means when reversing the direction of the gears, there is an amount of travel for the leading gear before it catches the following gear, this is called backlash. It is an extremely tiny amount, but it compounds on itself each time the gears reverse direction. It is my understanding that a combination of this backlash and imperfect homing/calibration on power-up of moving lights is what causes all moving lights to not precisely hit the same exact point on the stage day to day. This happens with all moving lights by every manufacturer due to the nature of gears.

Traditionally before A3D, we combat this with reference Presets, using known points on the stage we can focus our moving lights as tightly and accurately as possible. Then each day, or after each power cycle, we put our moving lights in their reference Presets, and make note of if they hit their mark as accurately as we need them to.

For example say I have a spike mark on stage at 0'/5'/0' for my reference Preset point. If after first focusing all my lights to that point and recording it I might come in a few days later, and notice Channel 8 is -1degree Pan off of 0'/5'/0'. If we know the fixture has not been physically moved, we know that for all our Presets and Focus Palettes in the show Channel 8 will be off by -1degree Pan. We can then in Blind select all our Presets or Focus Palettes and do "Ch.8 Pan + 01 Enter", and this will correctly update all of our Presets so they all go precisely where they should. Macros can of course make this a much faster process, but the steps remain the same.

To expand on our example let's say I also have 4 FPE points at the corners of our stage recorded, and on day 1 I used those points to Recalculate the A3D fixture positions so A3D and reality match. I can use XYZ data and type 0'/5'/0', and Ch.8 would precisely hit that mark. Now it's a few days later, and as before Ch.8 is -1degree Pan off of 0'/5'/0', and we know the fixture has not been physically moved. I can update our Presets recorded with Pan/Tilt data as we did before to correct for this, and all our recorded Presets will play back exactly as we want. However now if I try to use XYZ position to send Ch.8 0'/5'/0', it will still be -1degree Pan off of that point in space, despite the A3D model showing it hitting that point precisely. 

I could correct and update the focus of my 4 FPE points, Recalculate, and then Ch.8 should be able to precisely hit 0'/5'/0' when asked to. But as I said, doing this will change Ch.8's position or orientation in A3D, even though the actual position and orientation of the physical fixture has not changed.

I would like to be able update my FPE points, so A3D understands what Pan/Tilt values will correspond to a given X/Y/Z point, without having the fixture's A3D position and orientation changed.

Does that clarify for you what I'm talking about?