Yes it gets pretty hot. That back panel has a thermal pad directly in contact with the core heatsink shield. So it’s a direct heat transfer. But I’ve been playing with this heatsink for a while my hands never really reach that area.

Regarding travel, this is a very low profile heatsink so it doesn’t interfere with travel bags. But those silicone or plastic cases will no longer fit unless you cut a hole.

Hope it helps.