I know this doesn't help but I think the file picker is by far the worst feature Linux has ever had. And our opinions are quite common among Linux users.
I give you 3 options and you google them and choose the one which suits you the best. 1. Change the boot order in your bios (Mint drive first)
2. Install package 'os-prober' and then update-grub (Win10 will appear in Grub)
3. Install rEFInd to replace Grub and choose everytime which OS you want to boot (set timeout by yourself). Warning: theming the rEFInd is known to be addictive.
During the year with LMDE5 I haven't faced any issues with it. I tried Debian 11 for a week and even an usable Rust-package (up-to-date) was pain to install. I'm not sure, but I claim that Mint Team updates some packages into the repo by themselves.
LMDE also includes flatpaks so they're up-do-date anyway.
Unfortunately I'm not. I'm running numerous Thinkpads until System76 releases their in-house produced Virgo laptop with hot-swappable mechanical keys and open source bios (Coreboot). It'll also have the trackpoint from Thinkpads.
I went from decade with dwm into Alpine + Sway and had zero issues. Actually the opposite, all the screen tearing and multi screen issues are now gone.
Hopefully LMDE6 is a game changer for the most popular first Linux distro. If the CosmicOS by System76 doesn't win that title.
My grandparents were 1,5 years with Mint but LMDE5 has now been for 10 months and it is awesome. Literally 0 issues since day 0 whereas Win7 and Win10 caused constant headaches for me over the phone.
There isn't any other IT company in the whole world which can compete with System 76 in quality of service. Truly stunning.