I think implementing “dither by slot” would be more practical and maybe even replacing dither “Every X Exposure” (since you will control it in every slot).
For example, if you run sequence with L and Ha (or other narrowband) filters, for lets say 3 hours.
You doing L - 2 min exposures and HA - 15 minutes.
For Ha it’s obviously you want to dither every frame, but if you set dither every 1 frame, in 3 hours
you will dither 90 times for Lum, were you can easily dither every 3-4 frames and save even more time.
So it may be easily done by doing:
Slot 1: Filter L, Suffix, 60 sec … Repeat 90, Dither (every 3 exposure)
Slot 2: Filter Ha, Suffix, 900 sec… Repeat 12, Dither (every 1 exposure)
Thank you for consideration!