absolutely!

scout: musk, anything involving it.
soldier: boot worship. he likes boots man what can i say. also petplay, get this man collared and leashed and get him drooling all over some leather boots and youre golden
pyro: huh. honestly not sure. fire, obviously, but i also think they’d like edging, teasing, hurting someone. especially just for their facial expressions
demo: blood, s&m, etc. he likes being hurt and he likes (all within boundaries) hurting his partner. definitely would hold his sword up to their neck as he fucked them from behind if he could
heavy: begging and edging, not super niche but considering him? he trembles at the thought of being forced to tears, begging and pleading to cum in his native tongue as english is not enough to do justice. maybe he’ll be allowed, maybe he won’t. he’s resolute and strong at first, but after so many times being denied even one mighty as heavy can crumble~
engie: he likes pits, what can ya say. he doesnt mind if he’s the one huffing them or shoving some poor sap’s face into his, he likes them all around.
medic: pissplay, spit, blood, unhygenic all around baby! get him tied down to the surgical table and use him as a urinal, and cut him up for good measure, smearing his blood around. (god i sound insane writing this)
or him being the one performing the uncleanly acts, might be even more thrilling due to his doctorly oath
sniper: besides the obvious piss answer, probably public sex or having an audience while having sex, especially with more niche kinks involved. he’s always so private and to himself, why not let a man be open?
spy: cbt, extreme bondage, humiliation. he probs faps to the idea of being tied up tightly in the air, blindfolded and gagged, only hearing degradations of his character while blows from a whip are delivered to his cock