In reply to Otto.

I’ve tested the block editor on the test forums site. Not impressed. Slowed adding a comment way down. Way too many options and gizmos for moving blocks around. Essentials like ordered and unordered list nowhere in site.

Why not just add a hidden parser for external image services to put a thumbnail in the post which opens into a lightbox?

Adding the block editor to WordPress support forums is a yet another solution in desperate search of a problem.