It's worth spending the time figuring out, I think. They do pro rated pricing, so play with it and make mistakes, it won't cost you much to create and destroy some servers if you start from the cheapest to play around with.
I asked another commenter here the same question that I'm going to ask you.
I was running a my own single user instance, but I had a hard time getting comments to come in to mine. Have you found a good way to get Lemmy to more reliably pull in comments from remote instances?
I would have to browse out to the original instance to see most of the comments, then back to my own if I wanted to comment (if it was under a comment that my instance hadn't pulled in, then too bad), then back out to the main site to continue reading. I found that process very tedious so I switch back to a more populated server which seems to pull in most if not all of the comments.
I have not noticed any issues like you describe. Everything seems to dtrt. To be fair, it could be happening and I don't know it, but I'm not going to go out of my way to look for comments that clearly don't like me, either.