Self-Heal Gene (S)

[RedSalamando]

Alright what's the secret to finding this gene? I'm 2 genes away from completion and I have got to be insanely unlucky with this one specific gene, it almost feels like your game is bricked if you beat the game without getting this one first before muddying the pool of genes with XL's.

My current setup is the reset method in Sardona Barrens with 2 Purple Ludroths and 2 Cephadrome dens for the maximum amount of eggs per reset.
I've tried with both G/R eggs and Normal eggs, about 200 eggs each, and still only (M) shows up.
It seems even after this long after the games release there's no hard evidence on how egg rarities work. The way I see it: Rarities give a guaranteed gene from the pool of random ones for that monster, one more gene for each rarity. So I've been going back to taking only G/R eggs for a roll at the 1/26. Normal eggs seem to give a roll about half the time, otherwise they just have base genes with no rolls. People seem to have some sort of confirmation bias on Normal eggs only rolling (S) to (M) genes, but they very clearly roll up to (XL)'s too, so I've stuck to G/R eggs.

[RedSalamando]

Of course I get it with 1 more hour of eggs after 10 hours of farming after making this post. Keep farming G/R eggs!