They didn't nerf motherlodes. Please stop spreading this false information.
I've mined 2,000 tons of Void Opals without abusing the AB-bug and got ~15t of (refined, not chunks) Void Opals on average per motherlode in 3.3.01
This morning I cracked 7 core roids and am now sitting on 106 tons of refined Void Opals. 106 / 7 = 15.1
The yield of motherlodes didn't change. You can still make 100-150 mill/h. Good luck finding a better source of income.
Yeah, that's my experience post patch - averaging around 15t per roid. The profits from mining never were as disproportionate as some claim though - I've been making comparable money from haulage missions for over a year (greater if anything).
Incidentally, I notice that it no longer tells me how many chunks were freed after detonation - is that a new bug?