I am playing around with Resolve Lite, and have a question about XML from FCP and re-exporting through resolve.
Project originated on the Alexa at 2K Apple Pro Res in Log C. Was edited in a 1920x1080 FCP timeline and exported in the XML format for resolve.
After coloring, to realign with audio, VFX, etc. I would want to export through resolve at ProRes 444 1920x1080, correct? Going from FCP - Resolve - FCP - Final output, does that cause any degradation?
Minimal inversive , i'd say.
Best is to not use any outputs from degrading edit applications.
I tend to avoid that until i got a master-of-desaster editor that went crazy with effects, time-changes and stuff he wants in anyway.
In all other cases try to grade from the source files.
But if they did the edit in Log-C and did scaling only the loss is acceptable
You could bump it down to 1080p, but there's no reason to do so. FCPX will keep your framing when you round-trip back into the program. Make sure you tell it to render out to 2K. If I understand you correctly, you don't have Alexa raw which is what would be preferable, but the ProRes should be pretty good especially at 4444. If you had the raw, you could just bring them into the media pool first, and then import the XML, which would relink if you tell it not to automatically create clips. In either case, you could export out at ProRes 4444 with great quality.
Also, in general, Resolve 11 is pretty good about keeping most FCPX speed changes, ramps, and things like that, so you don't have to bake them in. You should check them after the round trip, though, because there may be slight translation errors occasionally which you can easily correct in the NLE. This is actually a huge advantage for FCPX-Resolve workflows.