Is there a programming option in patch for offsetting Pan/Tilt values?

I don't know if you can directly add an offset, but you can do the equivalent by copying the fixture in patch and changing the range on the Tilt parameter from where it has User Min -100 and User Max 100 to say User Min 0 User Max 200, which should mean if you had the tilt parameter at zero in your cue it would now be outputing the DMX value that setting it to -100 would have output previously .

Not to be an I Told You So or anything, but for future reference.... This is where Focus Palates et al come in handy!
You can readjust your focus points without having to bother with altering any cues.
If your units have the same focus in half the cues, you only have to adjust your points once as opposed to in every cue.

(Even if you offset your values, the positions might not be exactly where they should be.)

You could try to edit the presets/pallets in blind. (or even directly in the cues) You can select your presets, then your channels and give the @ +90 command. If it is the other way you can do a @+-90. This will edit the current values by + or - your given value. Of course you will have to check them all, but it should save you some trouble.

Thanks to everyone for the feedback! I appreciate it a ton.