Maybe Qt 5.12 for macOS?

[Daniel]

There are a couple of annoying problems with the current LyX UI under 
macOS, like tabs disappearing (see 
https://www.lyx.org/trac/ticket/10571) or cursor getting stuck in 
widgets (https://www.lyx.org/trac/ticket/11116). I am wondering whether 
a leap to Qt 5.12 (LTS) might help to resolve those. I would be happy to 
try if someone can compile a macOS binary from stable for me.

Daniel