Sorry, the "you can't do RGB in LP" carp sandwich needs to end. It is just absolutely not true!
It's not the best image on earth, but here is my Corona Australis, shot 300 metres from Canberra International airport, which is surrounded by 24/7 lighting, including the RAAF Fairbairn base, and all the Defence buildings around, plus a Bunnings Light House the other side of the runway, plus a shopping centre...and a highway with exit ramp lights....and so many LED and Sodium street lamps around... and this is just 8hrs with an 85mm refractor AND an OSC CCD.
https://www.astrobin.com/full/343506/G/
...plus an ultra-faint PN done with the same rig, same location:
https://www.astrobin.com/full/339252/D/
So, whilst these are not brilliant, it also shows the LP vs RGB nonsense is precisely that - NONSENSE.
As Nike says - JUST DO IT!