Preset Merge ignores Feature Group Filter#332

steps to reproduce:
1) select fixture and put some values in programmer for dimmer, color, position
2) record position preset somewhere in an empty memory
3) clear programmer
4) select same fixture and put some new values in the programmer for dimmer, color and position
5) merge the position preset.
6) clear the programmer

when now activating this position preset:
observed behaviour: if position preset is active, the dimmer and color values are also loaded/visible.
expected behaviour: if position preset would be activated, only the new merged values should be loaded/visible.

It looks like merge ignores the prest pool filtering.

Nicely written bug report!

The issue itself is that all functions instead of just position functions are merged into the preset.
As such, if this preset is used in cues, the values in the cues will reference the preset, which will carry over into future shows - and once the issue is fixed, those values will not be updateable anymore.

We actually found a way which allows the user to still update the functions in the preset, while disallowing to add new functions.