I still think any carb clean should include opening them up
I was just about to ask you if you would think it should still be opened up.
I do know some very competent and fastidious marine engineers, the good ones are nearly always difficult to get hold of or you have to book them weeks in advance. It's the same with rogue or useless car mechanics/fitters, they are usually available at short notice and the good ones are always booked up.
When Ed stripped my carb down he insisted that I buy the cab kit which replaced needles, gaskets and seals etc. He was fastidious about the float adjustments too. Consequently I would have thought that even with an ultrasound clean, as you have said you would still want to replace bits and pieces or at least inspect it.