I don't think server side is in their dict without a dash. I don't know how to type dashed words in swipe. SwiftKey cant do it either. Long words usually work very well though. That's most of what I use swipe for. Short words I tap, long words I swipe.

e.g.,

Broadside Surfside integration financially illiterate calibration fantastical proliferation haphazardly horrifically striations proliferation (all typed first or second try except antidisestablishmentarianism which admittedly I got carried away)

Interesting, I just tried it and it got server-side the first try, although it wants to insert a hyphen. I did download the larger dictionary from their site.

I'm sure they will, version 3. Don't let the perfect be the enemy of the good.

Try the keyboard or the training. It's better than GBoard in some ways.