Hey Paul,
The 6.3.2 version seems to work with Dooble about as well as the 6.2 version as far as I can tell - no better, no worse. Maybe it takes longer for YouTube to hang, but it still hangs (I was able to play a video once for about 5 seconds before hanging). Other apps tried (qBittorent, QtTube, Scribus) all have the same issues with both versions, but nothing new. The examples also seem the same - anything with 'QML' or 'Quick' in the name and some with 'SQL' don't work, but everything else I tried so far does... thanks!
EDIT: BTW - your Dooble github site does not have a facility for lodging issues, is that intentional?
Regards,