There have been quite a few disappointed GGLs recently, whether due to ground services or the lounges at LHR & JFK.
Having been GGL since 2014, and GGL+ since 2018, I've noticed a drop in levels since mid 2021 - but I attribute that to the number of people who have remained at GGL level due to extensions etc.
In terms of the CCR, the regulars know it's become a lot busier, but that will change later this year at the request of numerous stakeholders (some of whom BA do listen to!).
For the OP, well done for binning GGL. I hope you stick to your guns but can also appreciate we all have moments where something doesn't go in our favour.
M
P.S. I am deeply upset that there is an aspect of T5 that CWS doesn't know about. I believe CWS should undertake a refresher course in the pipework & electrical diagrams of the Terminal. Only then, will I re-consider your position as The Oracle.