I use TVDE's drivers for my QHY5 under Maxim... they work fine.. I never ran the QHY8 + QHY5 together under maxim, so I cant speculate on what would happen if you were running the 8 under ascom and the 5 under TVDE drivers...
Peter, May I make a rather general observation... It seems you, like myself, have gotten caught up in the "TOYS" side of astro imaging.. From personal experience let me say, This road is annoying at times... You end up spending most of your time learning new software, new mounts, cameras etc... and very rarely actually imaging... You have been warned...
I've now blown my astro toy budget for the next 12 months, so I think im going to have to settle for imaging rather than learning new toys for a year or so!
