Default Convert carrier branded to stock software?

I've got a M8 from EE in the UK, which comes with some carrier additions in the software. It also tells me that I'm up to date, although I know there is a newer version out there. It's obviously not been approved my my carrier yet.

Is there anyway I can convert my device to the standard firmware, after unlocking on HTC dev?

I suppose I could just flash a custom Rom?

Would my carrier know / care if I did this?

Cheers
Stewart

Sent from my HTC One_M8 using Tapatalk
HTC One M8 : ARHD 8.1
Asus Nexus 7 (2013) - 32Gb : ParanoidAndroid & Stock 4.4.2 using MultiRom