Honestly, if your sites are already built in Webflow with no issues then I wouldn't bother migrating over to Framer. I don't see the benefit unless you're building custom React components to slot into a Framer version. Webflow is just as powerful if not more so. And that's coming from me using Framer, not Webflow, and being a total fanboy. I'd just build new sites in Framer if you want to move away from it for your own design/build ease, or other personal reasons. No need to put yourself through the hassle of migrating everything unless you need to for some reason.
I'm currently using Framer. I have a full-stack web dev degree and have been building for over 6 years now. I actually ended up building most sites in Squarespace believe it or not, just cause clients needed something intuitive and simple for them to maintain afterward. I considered Webflow many times but just never pulled the trigger, then recently Framer has drawn my attention so much that I've completely leapfrogged Webflow and went to Framer. (Not saying I'll never build in Webflow, just my story). I use to use Relume for sitemaps and wireframes to then build in Squarespace too, but obviously, there's significantly more flexibility in Framer or Webflow. I'd love to see Framer added to the Relume world.
Yea, but is not that well supported yet sadly. The workflow most people seem to try out is Relume to Figma, then Figma to Framer with Framer Figma plugin. Even with that flow the results are patchy and Figma to Framer often messes up the Relume build and it's almost easier to just rebuild everything in Framer piece by piece. I still use it for sitemaps and wireframes, then design in Figma, and build in Framer. I'd love to see Relume make it actually compatible with Framer similar to how they do with Webflow.