A well sorted RC has the edge over big refractors for imaging small DSOs?

I’m now seriously thinking about a retirement imaging set up, it will literally be a once in a lifetime opportunity, and it will be a collaborative project so it needs to be the right decision. It looks like an EU purchase so starting to get a bit nervous about what might happen to the GBP post Brexit. I have been imaging with am AA 102 mm APO on a Mesu 200 and Moravian G2-8300 and enjoying it immensely, but my favourite targets are galaxies so a scope with more aperture and focal length is

I don't know which is best but I concern myself only with the practice, not the theory. I imaged with Yves' 14 nch ODK for two years and now go after similar targets with a TEC 140. The big one was working at 0.66"PP, the TEC at about 0.9. The Barlow question is a good one but Roland Christen would not agree that the Barlow has no place. If you want to blow the standard theory out of the water have a look at this capture by Julian Shaw using a 2x AP advanced barlow at about F15 in a 6 inch