For good globulars the key is to protect the core and not saturate the stars. So my approach is to keep exposure times short and skip the luminance filter and combine all RGB filters to make a luminance stack. This was in a red zone so I was pleased with the depth I got even a couple small faint galaxies showed up on the left.
M12 globular cluster in Ophiuchus
C14 @ f/6.3 ASI1100GTO
ASI1600MM-c 1.25" Orion RGB filters
30 subs each @ 30 seconds
captured in Nebulosity processed in PI & PS