Ya, that's probably for the best. BTU would get it first because that's the stock, unlocked UK region code. Carrier branded and any other modifications would come next.
You don't really need to be in a huge hurry to upgrade anyway. I've not had much time with this update but if it got really sluggish earlier (then seemed to right itself again) and if it's anything like the Portugal TMN MC8 firmware then it's actually a lot less stable than the MC8 firmware. My phone flew on Gingerbread. It seems to be more at a brisk jog on Jelly Bean, occasionally slowing down to catch it's breath and sometimes collapsing in exhausting when streaming video.
The BTU iteration may be modified and improved though. Time will tell I guess.
You don't really need to be in a huge hurry to upgrade anyway. I've not had much time with this update but if it got really sluggish earlier (then seemed to right itself again) and if it's anything like the Portugal TMN MC8 firmware then it's actually a lot less stable than the MC8 firmware. My phone flew on Gingerbread. It seems to be more at a brisk jog on Jelly Bean, occasionally slowing down to catch it's breath and sometimes collapsing in exhausting when streaming video.
The BTU iteration may be modified and improved though. Time will tell I guess.

Very odd. Thanks for replying though.
You must have misread my last post or something.