Just downloaded the latest Beta/RC for Affinity Photo (Mac only for now), and to my surprise, found it will now open X3F files from my DP2M.

Now, before you get too excited, the support seems to still be a bit rudimentary. Colours are off - uneven across the frame, but with some multi-selecting with the white balance tool I've been able to get something tolerable. More playing is definitely needed, but there is some promise there.

I've been playing on and off with the various betas, and Affinity Photo is shaping up to be quite a nice option for Mac users. Performance is pretty good, even with the Merrill files.