Right, only one side of the connection needs an open port (and most clients will let that be either seed or leech side)… this is why having an open port on your end is useful if you’re downloading, since you can download from seeders that don’t have an open port.
If you want the instances to sync, you just need to sync the directory. (I currently use nextcloud sync for this, but in the past I used synching and before that btsync)
If they dont try to modify the files at the same time (with sync delay) there won’t be any issues. If they do grow out of sync, you can fix pretty easily with db repair.
I mean people said this about SponsorBlock, but it turns out you can crowd source the timestamps… If you built an easy enough UI.
worldcat lists the institutions with this book https://search.worldcat.org/title/1048005393, you’ll probably have to show up in person. You may be able to do an inter-library loan if your local library doesn’t have the book, you could get it from a sister library. However, the only public library that lists having the book is the Austin Public library in Austin, Texas.