currently there is almost no real difference in what class U pick when U go into Geode caves unless that class has a good dodge roll (Gunslinger, Fae, ect)
so my suggestion is like subclass give class a "small" buff when in cave when you are playing as that class this would be nice in a future update otherwise....
i will now try 2 list examples for all classes but your could probably think of better ones..

Vangardian: +jump and/or when U grapple a BLOCK the block takes a little more dammage
Dino Tamer: critters will come closer to you more often
Clormancer: you get a little GAS refill from the exploding flowers
Reverent: you lose less GAS from attacks in caves/or the thumper is boosted (can stack with other thumper upgrades)
Luner Lancer: your grapple is a little better (grapple upgrades can stack with this)
Tomb Raiser: this class is normally depicted as undead so it loses GAS slower because it does not need to breath
Bommeranger: lasermancy fom the omnitool damages blocks faster (tool upgrades can stack with this)
Pirate Captain: gets more item drops (because magic find subclass)
Shadow Hunter: Lasermancy form the omnitool has more range (tool upgrades can stack with this)
ice Sage: Barrier Generator lasts longer/is stronger
Candy Barbarian: better energy regen (can stack with N-Charge upgrades)
Neon Ninja: moves faster then other classes and/or more jumps
Dracolyte: lowers cooldown on Modules (yea this is ware i ran out of good ideas)
Fae Trickster: has more horizontal movement with rocket boots (can stack with other rocket boot upgrades)
Gunslinger: has more Vertical movment with rocket boots (can stack with other rocket boot upgrades)
Knight: pathprinter works better (can stack with other pathprinter upgrades)

overall the update is fun so far this idea could be used in the future if its "to hard to code" i gess

if any one has better ideas respond to this if U want