I used to do this but I found it downloads needed language files in the background. So every time it updated, I would clear all the app data, open it again on something innocuous, like a text file, toggle each language I used. Not knowing how long it would take, I'd wait until each seemed to be behaving, then disable network permission. I still don't trust that it doesn't send data off via Play Services.

Now I use Heliboard with the swiping library added. It's not perfect, but has improved, and at least it can give more than three correction options (long–press centre suggestion with ellipsis below).

I really miss Keymonk — two–finger swiping, accurate, and no crap.

I do usually this, but recently on older phone (using it temporarily while I buy new) I had to reinstall it and found out, it didn't provide any word suggestions for ant language other than English and even gesture input for other languages didn't work, so at least during initial setup it must have (now?) internet connection most likely to download dictionaries (I thought they used to be included in past, never noticed this before), after allowing the connection, setting up and then disabling the connection, it works fine