If a removed Mastery was once a Cluster Jewel mod, please add it back to said Cluster Jewel(s).

While I'm sure there are others, the one that immediately comes to mind is "Supercharge" which makes non-crit Lightning damage Lucky.

If the removal of the Mastery was only to nerf early game leveling for skills like Spark, then adding the mod back to the Lightning large cluster jewel keeps it in the game at least, but it will not be easily accessible in a race.

I'm looking to play around with a non-crit Vaal Lightning Arrow build in 3.21 and it would be a real shame to lose this passive completely.

Yes especially since the reasoning given originally was "don't worry a lot of the removed cluster notables were added as masteries".

they added that affix to voice of the storm amulet (breach item), so yeah you have to sacrifice amulet slot if you want that. Tbh it was a bit too powerful to exist on the skill tree

Oh nice, thank you for pointing that out. I totally missed it. Well as long as it exists somewhere I'm happy with that. It is quite strong, I understand why they wouldn't it so readily accessible.