When rotating a block next to Snad it seems to update faster causing growth to happen a lot faster. Here is an example: https://gyazo.com/7e097927bee79a7013bec994778ade4d - although I'm using a Chisel and bits block in the gif (and thought was the cause of this) it happens with vanilla minecraft blocks like stairs as well.

In the modpack I'm playing, Forever Stranded, which is a hardcore pack, this makes the pack a lot easier in the early game, and possibly midgame as well as you don't have the infinite water mechanic as in vanilla, but must rely on ex nihilo mechanics of making water - possibly using cactus.

Anyway, hope this was detailed enough.

This issue is because the snad block is based on a falling block and so the trigger for this goes in the update method
Pistons also work iirc

This wants to move out of updateTick and into randomTick making sure the block is set to tick randomly