Combo types that work on layers & FFCs

[idontknow]

What combo types work on layers? And which ones work as FFCs?

Here's what i know so far:
-Damage combos work for both
-Auto Warp works for FFCs--not sure about layers but probably.
-Eyeball combos works as FFCs--again, not sure, but I think they work on layers 1 & 2 as well

I think the following types should work on layers & FFCs as well:
-Direct Warp
-Stairs
-Sensitive Warp
-Step->Next (and all related combo types)
-Step Trigger
-Teasure chests
-Slash
-Statue
-Pound

*Please correct me if i'm wrong in assuming these all dont' already work on layers or FFCs. I haven't intentionally tested all of them to be quite honest but i'm fairly certain i remember them not working or hearing that they dont work as layers/FFCs.

Think about it--the ability to place warps, triggers, & treasure chests anywhere on the screen, not just at exact combo positions. Plus, the ability to have moving warps. You could make whirlwinds by having a moving FFC be a "warp" type combo (like Direct Warp or Sensitive Warp) These would also be key for custom bosses.

[Archangel]

Sensitive Warp does not, I can confirm this.