You’re right, individual pieces won’t make UV unwrapping much easier, or more enjoyable for that matter 😁
My basic rule is simple:
Plywood and similar I treat every cut edge as a uv seam.
On solid wood wrap face and edge grain around the piece together with only one seam, joints are usually seams too. Ends depend on how you want the grain to run. More on that in Chapter 3. 😉
Looking forward to your kitchen.