I only use FOSS ones. I hop between florisboard and unexpected keyboard, and I gave heliboard a shot again recently because it has the swipe/glide typing but I couldn't stick with it because I was missing other features, so I'm back on floris.
Since I only use open source keyboards, I'm not really concerned about privacy...so no blocking of internet access.
I also thought about trying out the clipboard history, and also am wondering if it's safe...
If you want to try FOSS keyboard again, HeliBoard is your best bet.