I'm stuck on android 9 unfortunately. I didn't realize how far behind it was.
Don't remember exactly when I purchased this phone, but it was a while ago. It's getting to the point where I need a new one, but everything kinda sucks at the moment.
Oh you can have all the google apps with Lineage and your phone is in the "fully supported" list. You just install the gapps package during the install process. I'm in the same boat as yourself - fully tied into the googlesphere so wasn't prepared to jump without it.
Not sure about your DAC AMP as tbh I don't know anything about them but if you're not sure you could do a backup, install Lineage with the google stuff, see if it works then revert if not. Total time I'd say would be 2 hours or so if you needed to revert (edit: plus reading time if this is your first time doing something like this).
It is quite annoying. Samsung has trimmed up their bloat and strange customizations over the years, but some things are still incorrect as far as I see them.
NetGuard can manage network access on a per app basis but it uses the VPN function to do so, while not actually being a VPN service. Sadly this means I can't be using an on-device VPN at the same time as turning off app data.