Update, I spend 7 days on the 27 monitor + mac mini + external apple keyboard + external trackpad, and I hate it! I don't move 2 times faster, is other wise two times slower. The big space helps for some things but is not mandatory to me.
What's the problem? I move so slowly with the
external keyboard and trackpad on the side, I miss the keyboard plus trackpad on the MBP, both tied one to each other and one on the top of the other! that's make a huge difference for me. And I'm not alone, there's some crazy ideas like this for that reason:
https://www.etsy.com/au/listing/1108619816/the-tre-2-o-apple-bluetooth-magic?click_key=178aba3d80256602797db44b3dc2d09e49f4e48b:1108619816&click_sum=8af777a4&external=1&rec_type=ss&ref=landingpage_similar_listing_top-2
Also due I need move across a bigger screen, I do things slowly, sometimes I miss where I want to point or do unwanted things, on my 15 inch screen I move crazy fast due I don't need move across a large screen, I never miss with the pointer.
Now, even with a $10 mouse I move quicker than the external trackpad. I want try the Apple Magic Soap, maybe not good ergonomics but have the gestaures, we'll see. The only bad is those clicks are annoying, the whole day listen "click" "click"...
So now I miss my MBP! I'll buy the M2 or well wait to the M2 MBP to use it without an external keyboard or trackpad.
Maybe I keep the 27 inch display to put it on the back! like you do, MBP on the front, Monitor on the back and that is, like the picture attached below.
By the way, I also hate how text looks on my 2K Asus Monitor, I miss the retina of my old 2013 MBP, yes! even that old screen looks better, even some people tell me the 4Ks don't look as good a retina dislay, overall I'll think on buy the MBP and the Studio Display and problem fixed!