I wouldn’t model that for subDiv, I’d bake all the bevels in there. Just get a good enough amount of Segments on the BevelModifiers. Create holes with enough verts/segments to support the resolution (view distance) you’ll need it in.
Booleans all the way. And keep it as Non-Destructive workflow (as much as you can), so you can make edits as you progress!
That would be a good project for testing some of the boolean addons out there.
I already made a post about the main options here: