Bleed explosion and Chest explosion

Hi, I crafted chest with explosion for my gladiator, but the more i think, the more feel like it useless

1) Does this stack?
2) Can chest explosion add bleed to enemy, or it same as bleedexplosion, which can't bleed\chain?
3) any good reason to use both of this? or it just extra 3% damage, which is nothing because gladiator already have 10%

1) pretty sure it doesn't stack, though I don't know which one would take priority

2)The chest modifier explosions don't count as attacks and you can't support them with support gems an as such have no chance to bleed. Though unlike the glad's bleedsplosions the chest mod just specifies "killed enemies" and not "enemies you kill" which should mean that the chest mod explosions can chain kill enemies in theory.

3) If you have 100% chance to bleed might not be worth it but if what I mentioned in 2 does happen (ie: the chaining) then the chest mod may be able to clean up enemies killed by the bleedsplosions

Multiple sources of explosion do indeed work.