I am looking for a good FOSS keyboard with suggestions and the ability to add multiple languages.
I use OpenBoard most of the time and it’s good if you are more privacy focused.
If you install a fork of it with that feature, yes. I personally use this fork: https://github.com/erkserkserks/openboard
I use AnySoft Keyboard. It is very configurable and has a lot of language options.
I use FlorisBoard
I was following this for a while but see it hasn’t received an update in a year now, is it abandoned?