You can do your own sync in a hacky manner - but if I were going down that route, I'd just choose one of the more open (and cheaper) alternative devices.
A friend of mine uses an Onyxbook (not sure what model) extensively for note taking and he seems pretty happy with it. Software developer with a bit of math thrown in, to get an idea of what he writes on it.
I'm being a bit future-looking here and considering alternatives to the gen3 reMarkable, not the current hardware. Specifically, the PineNote seems like it could fill the niche for me.
The Onyx Boox series come in different sizes and are just Android with a custom launcher, and they're cheaper and with more choice (most notably regarding screen size).
Caution however, the company violates the GPL, which might be a deal-breaker for some.
I got a Supernote and its a bit cheaper and has really great features. Remarkable shies away from anything but writing, so sync is limited - while the supernote has great calendar sync thats come in handle for note taking.