Sympathies, Chenks.
It can be very hard to get the TV licencing harassment mob off your scent after they get the slightest whiff there’s anything amiss, even when they are quite obviously wrong.
As mentioned in a different thread, Apple TV iPlayer continues to work without sign in, but only in SD. We have therefore signed in on the smart TV using other half’s long standing BBC account, which may be a better idea anyway as the licence is in her name, not mine. Otherwise, as you say, 2+2 might = 7.
One irritation since signing in, when starting a new playback, we now often get a 30 second advertisement for some other program. I suppose by being signed in, BBC are now ‘profiling’ the user’s tastes, and feel able to show ads that they think are relevant. The adverts can be easily skipped, but still very annoying, to me at least.