I take a few days (mostly) off-grid bikepacking around the Highlands after what seems like a loooong 18 months, and completely miss this Block Gap thingy.

IMO it needs to be opt-in or at the very least opt-out without merely setting styles.spacing.blockGap to zero. Additionally it needs to be adjustable/removable on a block-by-block basis.

There are going to be countless times when a gap is not wanted, for example multiple Group Blocks each with a background color, you usually doesn't want any white space between them.

Trying to get into the mindset of a non-developer, I can envision users being flumoxed when they are presented with a gap they didn't expect, and have no obvious way of removing.