For theme developers, would you address best practices for blocks?
Specifically, custom blocks - function plugin or style/theme? Which is faster - creating our own blocks or loading a block library?

Will we - as custom theme builders - be expected to keep up with custom function plugins? Creating one to be used on all our themes (that we can then upgrade) defeats the purpose of a small custom plugin doesn't it? I would love your thoughts on how we best integrate custom blocks and styles and patterns!

Thx!