And somehow it has way less blooming than other mini-led displays I have used. Not clear how they pull that feat off exactly

Most likely, they have more mini-leds and/or more ability to independently control them. Of course the localized "blooming" of mini-leds is a lot easier on the eyes regardless than the all-around bloom of a backlit display.

(Better for the battery too, if you can keep most of the screen dark.)

It is not even close. Pretty much any OLED is so much better