Having Tractoring 23 as a skill be trainable with a boss kill is cool, but it probably sucks for classes that might not be as capable to clear the Fallen Minelayer boss D:
-
Seer, SD, and Sniper can reasonably achieve stealth, but the Minelayer boss + its guards are fairly capable of seeing you through stealth (12 vis detectable by the boss at ~1.5k distance). While you can stealth against the mines to prevent them from exploding, you'll have to be tractoring or shooting the guards, so they'll be able to detect you and detonate anyway.
-
Tractoring mechanics mean low-thrust classes like Seer and Sniper suffer pretty badly - you end up being dragged back into the mines/boss pretty hard, unless you bring a +density enhancement tractor for the boss.
-
For classes that rely on bot DPS like FC and ShM, Fallen Minelayer is pretty AoE damage heavy - the mines and AoE torps can be rough for a mainship + bot fleet that can't get out of the way quickly enough - and FCs/ShMs tend to not have a lot of wiggle room being as big as they are in a pretty tight arena.
-
On that topic - the fight takes place in an asteroid ring, and mines spawn if you stray too far out of it - range is kind of a negligible trait in this boss fight if the boss isn't next to the mines, and there is a tendency for the asteroids to get in the way of non-radiation weapons. Snipers and gunners will end up needing to fight closer than their further engagement ranges.
-
Between the elec cost of tractoring, denting mines, and clearing guards, the boss arena has no suns/opportunity for out-of-combat regen, and there's a lot of elec that the fight will use. Bank-oriented classes like Gunner, Berserker, or FC run the risk of running out of energy before they finish the fight.
I think it'd be reasonable to let Tractoring 23 still be trainable through the Minelayer kill, but it should be optional, and the skill should also be trainable with tokens given how Ruined Sanctuary's balancing issues are.