I'm not the target for this particular product either and you and I use our MBPs in pretty much identical ways. I will say though, if the laptop's hinge allowed reverse clamshell like the Yoga, then I would consider the premium for a feature I would rarely use. I like the idea of a tablet, but any time I'm seated with one, I'm either doing something I'd do on my phone or doing something that I'd rather be doing on my computer running a desktop OS.
Unlike you I don't see myself switching to the Studio or Mini. My MBP has been extremely performant and its capability of on the go work makes it the perfect product IMO!
The set of people who use convertible laptops in tablet mode seems tiny. It’s one of those things that looks like a great idea but doesn’t pan out in real life. Everyone uses it once, says “cool” and never uses it again. 13” tablet that weighs as much as a laptop is not a great form factor.