Since yesterday, the really cool fork of openboard with active development and support of adding a swype library manually, got rebranded into Heliboard. A release on izzyondroidrepo and fdroid should be coming soon.
PS. If you are using the old fork you have to remove it first and do a backup of your settings.
I think it must be really hard to implement something that translates a bunch of seemingly random vectors to the closest resembling word.
It’s a bit like T9 typing but in reverse. You do an isolation of which words can be constructed out of every key your finger slides over, assign higher weight to the ones where sharp turns or longer dwell times were, and then take the most statistically likely result, and suggest the next 3 possible results in the top bar.