I will tip anyone that give me the info?

Where do we get them? Any required ilvl? Or specific zone, bosses?

final bosses

when you say final bosses do you mean the boss you can enter from killing citadel bosses?

From what I've read, they only drop in T16 maps with +2 area level from Corrupted & Irradiated map mods
I've done 10+ of those maps so far which are pretty rare to find and still haven't seen a level 20 gem

min level 82 to drop.

Use at level 90

Drop rate is rare AF, level 93 before it dropped... and its exponentially harder to level after 90.

try breaches and Mirror. Along with the +2. Thats how I got mine.

Yeah I've run breach on almost all my T16s +2 just no luck on the skill gems