Hey there friend! Sorry to hear about your woes. From my understanding in practice, ExFAT is usually better as more of a universally readable storage system for external drives. Think, using the same portable drive between your PS5, friend's mac, and whatever else. Great for large files and backups! Maybe not as much for running your OS from.

My approach and recommendation would be that you don't want OS's seeing each others' important business anyway. Permissions and stuff can get wonky for instance.

So your core Linux install can be something like EXT4 or BTRFS. I like BTRFS personally because you can set up recovery snapshots without taking tons of space. It does require a little extra understanding and tooling though, but it's worth looking into. (There's GUI based BTRFS tools now though. Yay!)

EXT4 is nice and reliable and basic. Not much to say, really! Both can do RAID 1.

Next, a /home mounted separately, this COULD be NTFS if you really wanted that sharing. (BTW there's some Windows drivers that can read EXT4 I think?)

BUT I feel more organized using a different way:

What I do personally is keep an NTFS partition I call something like "DATA" or "MAIN_STORAGE" and I mount this into my /home on Linux. It's usually a separate, chunky 4TB HDD or something.

On Windows this is my D:\ drive, and it's also where I store my project files, media, and whatever else I want easily accessible. Both OSs see those system-agnostic files, but are safely unaware of each other's core system files.

In Linux, you can mount any folder anywhere, really! You can mount it on startup by amending your FSTAB on an existing install or setting the option during installs sometimes.

So the file path looks something like /home/MonkeMischief/DATA/Music

It's treated just like any other folder but it's in fact an entirely separate drive. :)

I hope this was somewhat helpful and not just confusing. In practice, it'll start to make more sense I hope! The important thing is to make sure your stuff is backed up.

... Perhaps to a big chonky brick formatted as ExFAT if you so choose. ;)