Product review sync plugin recommendation

I have three woo sites which carry many of the same products but are marketed to different customer bases. Not all sites carry all products, but one site has everything. I'm currently using CusRev for reviews of all three.

My primary goal is to be able to show product reviews from any one site on all three sites. I guess that means syncing this one thing both ways, if possible.

It would be nice if I could also do inventory management from a single location.

My constraints are:

The sites have been up and running for a long time so I'm not starting from scratch.

As always cost and learning curve are a bit of a consideration.

Any suggestions, comments or thoughts are welcome. Thank you.

Edit: Thank you to everyone who took the time to advise me. I really appreciate it and I got the job done. Thank you, thank you thank you!