It seems to be infuriatingly difficult to have something ignore the pawn capsule on a character, yet collide with the mesh underneath. As I understand it there some form of ignore collision inheritance going on - so since the mesh is a child of the capsule, if the capsule is set to ignore say a custom collision channel, then even if the mesh is set to block it, it will ignore.
The logical way around that would seem to be making the capsule block all, but making the custom collision ignore the pawn channel, just colliding with the mesh (which is world dynamic). However after numerous tests, if you in any way attempt to ignore the pawn channel, it will ignore everything.
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It’s not a trace, just a collision between objects.
To give a bit more description, if you have a custom collision channel: Spell, and make a fireball with that collision channel.
Set the spell channel to ignore pawn, but block everything else
Set the player capsule (which is pawn) to block all
Set the player mesh (world dynamic) to block all
In that test - the fireball will pass straight through the character, which seems more like a bug than an artifact of how the collision is meant to work. It’s possible my understanding of the set-up is just way off, in which case I’d love to hear what I’m doing wrong, but I feel as thought it may be a bug.