How do you figure it would have been cheaper to install the plug-in version? It would require a GFCI breaker for code compliance (~$100) and an industrial/EV rated 14-50 receptacle for safety ($50-75). Hard wiring doesn't require either of these, so should be less expensive.
Just to make people aware that it's out there now. I'm assuming there's some bug fixes, so if someone is having FP issues (as you are seeing) they could try to force the update and see if it helps with the problem.
It will likely get pushed to all Android users at some point, as has been the...