In the UK there is no mandatory content for the 1 hr training flight; the ‘silly AIC’ gives guidance. But it’s actually pretty pointless guidance as to follow it to the letter would both make the training flight more extensive than a re-validation proficiency check and make it virtually impossible to complete in one hour!
‘Far better IMHO to have demonstrated two 45 min international passenger carrying flights with some IFR than 60 minutes of just keeping within the PPL test standards for various manoeuvres!!’ – absolute tosh, in my opinion. The idea of the SEP Class Rating training flight is to refresh basic flying skills; there are no ‘test limits’. Presumably your European FI would be happy for you just to fly him/her to lunch and back without having done anything more tasking than 2 take-offs, 2 landings and a bit of straight and level. That is stretching credibility rather.
If you taxy out to the holding point and just sat there for 50 min, I would argue that you’d hardly taxied ‘with the intention of taking off’. However, if having called ‘ready for departure’ the air traffickers held you for a while then yes, that would be considered as flight time.
There’s so much nonsense talked about the training flight; it’s just a chance to brush up skills with the helpful guidance of a FI. It’s not a test and the only requirement for the logbook entry is to confirm that the flight was satisfactory for the purpose of rating re-validation. But it must be a single flight of at least 1 hour!