Why do Trace and QOnly differ where they can be used?

To use Trace in Blind you need to use it before the Enter.
Channel 1 is Tracking at 50% between cue 1 Thru 10.
In Cue 5 in Blind, 1 @ 75 Trace Enter, will track the level back to cue 1 and it will track Thru 10.
Or Cue 5 in blind again, 1 @ 75 Trace QOnly Enter. Will trace the value back to cue 1 but in cue 6 it will go back to 50%.

I see certain things work and certain don't and the order of QOnly and Trace matters. Here are some things that work or don't work in blind:

YES: Ch 1 CueOnly @ 50 Enter
NO: Ch 1 Trace @ 50 Enter

YES: Ch 1 @ 50 CueOnly Trace Enter
YES: Ch1 @ 50 Trace CueOnly Enter

YES: Ch 1 @ CueOnly Trace Enter
NO: Ch1 @ Trace [error here]

I see certain things work and certain don't and the order of QOnly and Trace matters. Here are some things that work or don't work in blind:

YES: Ch 1 CueOnly @ 50 Enter
NO: Ch 1 Trace @ 50 Enter

YES: Ch 1 @ 50 CueOnly Trace Enter
YES: Ch1 @ 50 Trace CueOnly Enter

YES: Ch 1 @ CueOnly Trace Enter
NO: Ch1 @ Trace [error here]

I'd also do the value and then Qonly or Trace. The modifier before the value is a bonus to users I would say. I'm surprised they would work.

Ch1 @ Trace is not a valid command, because @Enter is removing a move command.
Ch1 @ CueOnly Trace Enter, is ignoring Trace and just using the Qonly.