With the posts I've seen on the forums since 5.8 was released:

Launching Quest in Play mode.
FAILURE TO LOAD GAME!
My Game’s Online Mode Doesn’t Work
Quest Encounters Errors and Freezes Every Time I Load
cant load game error
Quest 5.8 Background Colour Issue
Unable to Launch Gamebook (Desktop Version)
Strange Errors since 5.8
Failed to load the game
Quest Desktop - accessibility issues
Show menu problems

...the last thing I'm going to do is install 5.8.

I realize bug fixes take time and there's no real way to estimate how much coding and time that involves.
I'm totally fine with that.

But please, issue a roadmap or plan or something -- communicate with us -- as to what's down the road for an approach to an eventual fix. Until there's a new, tested release higher than 5.8.0, I'm sticking with 5.7.2.