Efficient backup/file management strategy for dealing with Windows/Linux dual boot system?

Novice synology user looking for some advice - been learning a lot reading other posts and watching videos, but not sure best way to implement for my current situation.

A few years ago I bought a ds920+ primarily to back up my main Win10 PC. The NAS has two drives running in RAID 1.  The Win10 PC has 4 physical drives - one for OS, one for steam game installs, and two for storing files, photos, videos, etc.  I initially set up separate daily full drive "PC/Mac" backups in ABB for each drive.  I also set up Synology Drive to continuously update a subset of more critical files.  All of that backed up to rotating external hard drives nightly (also rotating on/off site).

I recently set up Linux Mint / Win10 dual boot on this PC and am primarily using Linux as daily driver now (not 100% there yet, but getting closer every day).  I still log in to windows every day or so to run the ABB backups, but having some issues getting all new/modified files on the storage drives to backup reliably (it's only ABB; Synology Drive works just fine).  I seem to have fixed some of those ABB issues, but not 100%.

Now I'm wondering if there's a more efficient way to go about this in general, and if I should essentially start over.

I can see continuing to run a full drive ABB backup for the Win10 OS drive.  And keep the games drive local (used by Windows only) with an ABB "File Server" backup or sync with Synology Drive.

For the two data storage drives shared by both OSs, not sure if these are better backed up as file servers via ABB, or if I should shift these files to use Synology Drive instead, or simply create a basic file share on the NAS that gets backed up to the external drives.  I don't really need to share these files across multiple machines simultaneously.

For completeness, I'm currently backing up my Linux OS physical drive to its own separate physical drive (not in NAS) with timeshift.  That same backup drive also has some steam game files on it that are meant for Linux-only use (I learned the hard way not to share those files between the two OSs). All of that should eventually be backed up directly to the NAS as well.

Any thoughts on a better way to manage this setup would be much appreciated!