Your position is quite a theoretical one: "the best SUT is no SUT".
Of course you always have to deal with compromises.
The weak point in matching is - and you are talking about it too - the phono stage.
When you have experimented with so many MCs and SUTs (and also phono pres) as I did and still do my personal conclusion is you need an excellent phono stage like the EMT JPA 66 or the Boulder 2008 avoiding SUTs. The funny thing is that the quality of the resistors you put on the personal cards in the Boulder is decisive for the sound. Such a small little thing!
You don’t need need investing a big sum on a phono stage when e.g. you go for a Manley Chinnok and use the MM input with appropriate SUTs.
You will be surprised what results you will hear and maybe you will change your opinion quickly.
Manually wiring of transformers is the best way you can do. Of course they are using small machines when doing so. 10 years ago I saw it at DaVinci Audio Labs when Peter Brem was still alive. I think in Japan some high quality producers like Hashimoto use it too.