The problem is Alex, in 30 sec subs, the cam is not really going to build up much heat from keeping shutter open etc etc. A LOT of the noise in DSLR's for astro comes from the heat from long exposure.
40 minutes of short subs isn't going to show much either compared to 40 mins of say 5 min subs, let alone say 10 min subs. I live in a horrid deep red zone, and I not only shoot unfiltered, with an OSC CCD (cooled), but I also shoot MINIMUM 10 minute long subs. I took this with an 85mm scope, OSC CCD, 10 min subs, next to Canberra Airport (8hrs total subs so far - going for 16 hours
):
https://www.astrobin.com/full/343506/F/ - and half of that 8hrs was done in 68% Moon... and Corona Australis is VERY close to the Moon at that.
You got nice colour balance and good focus too this time Alex. Well done.