Does anybody know if fire ticks do more damage with a higher leveled bombs or is the damage fixed by depth (I am not talking about initial damage)
I've tried looking for damage tables and searches, but the only thing that comes up is about fire damage to players.
It is the same, unless the bomb is being used in a depth too deep for its star level. So a 2* Fiery Vaporizor is going to have the same fire ticks as 5* Ash of Agni in Tier 1. Once you get to Tier 2 though, the 2* bomb should drop off rapidly compared to Ash's fire ticks. (I think it is Tier 2 when it drops off, can't recall.)
A 4* bomb is going to have the same ticks up until you reach Tier 3, then it isn't as effective. By Depth 28 it should be doing about 1/2 damage compared to the 5* version. I think it probably does the same "damage" through the third tier, but the enemies' defense increases as one goes deeper, so the bomb removes less HP from the target. Hard to determine if that is what is actually happening.