"Flash issues" you say?
Having just re-installed my laptop, can't say i've noticed any particular hic with stable.
Have been testing Vivaldi's latest and i find it pretty good.
Still not ready for the road, but it sure looks promising!
More than Windows 10 Edge which won't even have extensions support by official release date of July 29.
Might give that Nightly Build a spin.
If my computer breaks, it's all your fault MilesAhead!