Fatshark, please make the Zealot versions of the Graia/Carapace helmets cross-class compatible.
Seriously, these are Guard-issue items to begin with, and there’s far more reason for a Guardsman to have a purity seal on his helmet than there is for a Zealot (or a Psyker, for that matter) to be running around with a voxcaster backpack.
Besides, the “Scavenged Graia Mk VA Battle Helm” and the “Kantrael Mk IVB Deathmask Helm” are the only currently-existing versions of this style of helmet that match the shade of green used by the “Relic of Cadia” heavy armour, or the “Protectus Pattern IX Militarum Heavy Battle Gear,”, or the “Veteran Squad Leader” armour:
It just makes sense, you know?