Greetings from BA32 HKG-LHR, which will arrive at LHR T5 i the early morning. I'll have a ~11h layover, before flying onwards in BA Club Europe out of T5 again (BA award ticket).
I'd like to have a shower, and then I'll have a couple of video meetings throoughout the day. I have BAEC Silver (OW Sapphire) status and also an Amex Platinum card and PriorityPass.

The Galleries lounges in T5 are dreadful (dated, dark, low quality food) and typically crammed.
Would it make sense to go to another terminal? Which lounge would you recommend in that case? CX at T3? QR at T4? Which one is closer to T5?
I was flying QR out of T4 recently and was blown away by their lounge. But I was flying in QR C, so I had access to their premium lounge. Flying BA metal, I guess I would only have access to their frequent flier lounge? Would that be a good option?

Or is it too much hassle to move between terminals, so you'd just suck it up at the Galleries lounge?