I didnt happen to see it mentioned but any issue with taking the barrel out as far as wear? I've been popping the barrel out for travel and dont want to cause an issue down the road. Also any issue with dry firing as far as breaking something hammer, firing pin etc?
I don't know about a problem with creating wear by taking out the barrel. It is pretty robust.
SDP factory ones have a steel bearing ring in the nose of the receiver that matches one on the barrel: unless you are reefing it & out lots per day (say as part of your load/unload drill or inspection) in a very gritty environment- should be OK.
Might have to watch damaging that alloy overhang dorsal to the receiver: that can get damaged by repeated clumsy barrel changes (steel on alloy).
What you might want to track is the locking notch on the left side of the receiver that retains the cocking handle to the rear: steel on alloy & it can wear. It can be re-profiled a few times but after that: unreliable to nil hold open.
No idea on the alloy or quality thereof on non SDP made AUG.