That was probably me. Joe, the alignment guru, has moved from there now to a garage in Leighton Buzzard Servicing, MOT & Car Garage Leighton BuzzardIt might be worth seeking a local independent to do this. Quite some time ago someone on here recommended Blackboots in Chesham for alignment. We were curious about our M3P and had it checked. Very professional and knowledgeable and they confirmed alignment was good and refused to charge us! Not saying it's an option for you but giving an example. I wasn't even aware that Tesla does the alignment themselves so they may be farming it out anyway.
He's offering the same services there and continues to be the best I know to work on Teslas in this part fo the country.
Tesla do carry out alignments themselves but I've found the quality of work to be patchy and the cost is just unreasonable compared to someone like Joe, who as you've found, charges a fair price for the actual work they do rather than having a flat "4 wheel alignment" fee.
Most of the time, these cars don't need all the geometry correcting. Quite often it's just a quick toe adjustment which shouldn't take anyone more than 30 minutes. Toe is the usual culprit when it comes to inner tyre wear and I've seen several Teslas come out of the factory with the toe not where it should be.
I'm also seeing more reports recently from owners of new Model 3/Ys complaining about vagueness in the steering on m'ways, which is aso a sign the toe may not be set correctly.
Regarding regular servicing, I've mostly done that myself to cars I've owned in the past if they've not been leased, so I've only visited a SC and had a ranger out a few times for warranty repairs over the last 5 years. Brake servicing, cabin filters, wiper blades are all straightforward if you have a few tools and a jack (and preferably a warm, dry garage), but I realise not all owners want to touch anything other than the steering wheel, so YMMV.