It’s really aimed at programmers, but for someone who is used to the better known proprietary versions (so with sketching and “shaping” with a mouse,), it’s barely useable.

Interesting, my approximation to an English r is more like a muted w than anything involving curling the tongue and still there’s a major difference between r and l sounds. (The r in my native language is also fairly unique, possibly regional.)

Edit: Just checked with a mirror and nope: raised tongue with the sides of the tongue pressing against the upper molars and a curled tip.