Unfortunately it really doesn’t. And it’s actually Linux that’s the bigger problem: whenever it decides to updates GRUB it looks for OSes on all of your drives to make grub entries for them. It also doesn’t necessarily modify the version of grub on the booted drive.
Yes I’m sure there’s a way to manually configure everything perfectly but my goal is a setup where I don’t have to constantly manually fix things.
My install does not seem to do this. I removed the windows drive when installing Linux on a new drive. Put both drives in and select which one to boot in the bios. Its been that way for about a year and, so far, grub updates have never noticed the windows install nor added to grub.
That’s with bazzite, can’t speak for any other distro as that is the only dual-boot machine I own. Bazzite does mention they do not recommend traditional dual boot with the boot loader and recommend the bios method so maybe they have something changed to avoid that?
If you install each OS with it’s own drive as the boot device, then you won’t see this issue.
Unless you boot Windows via the grub boot menu. If you do that then Windows will see that drive as the boot device.
If you select the OS by using the BIOS boot selection then you won’t see this issue.
I was bitten by Windows doing exactly this almost 15 years ago. Since that day if I ever had a need for dual-boot (even if running different distros) each OS will get it’s own dedicated drive, and I select what I want to boot through the BBS (BIOS Boot Selection). It’s usually invoked with F10 or F11 (but could be a different key combo.