Khürt, I’ve been using WordPress Crossposter almost since it came out and have never had any major problems with it. (I’ll note that I’m also using the Classic Editor instead of Gutenberg, so mileage may vary with that particular variable.) I think the developer still actively uses it and is open to fixing bugs/issues, but other than a few known quirks (which are usually issues with only supporting a subset of what is capable of) I suspect it’s fairly solid. Are you having particular issues with it?

Syndication via POSSE from .org to .com using Syndication Links is doable, but would require some reasonable amount of coding as a plugin/sub-plugin to enable Syndication Links to handle it. If you wanted, you could register an issue on the Syndication Links GitHub repo to start a discussion with others or potentially attempt to hack on it yourself. I’m not sure it would rank high on David Shanske’s to do list since I don’t think he has or mirrors content to a .com site and there are other means for doing it.

Another option I’m aware of is the Social Network Auto Poster (SNAP) which I think also does syndication to websites, though I’ve never tried it personally. I suspect there are likely other methods/plugins, but haven’t had the need to try to use them.

Another basic fallback is using any number of RSS plugins which could be put on a .com site to pull in content from a .org-based site.

I’ll also mention that though I do this sort of syndication myself, I’m honestly not sure how valuable it really is in the grand scheme of things, and have been recently evaluating if I’m going to continue doing it. Have you gotten more readers/reach or experienced positive benefits in doing it yourself?