I try Orion periodically but always find it to be buggy

This is why I started using the Orion browser. It's not perfect, I've had a few freezes and occasional weird behavior but well within the "tolerable" range for me, and not noticably worse than the glitches that any ad blocker causes on some sites.

Does that really matter if virtually no one is going to develop extensions according to the Manifest v2 spec?

Developing for that spec means your extension is incompatible with idk, 98% of the browser market?