Yeah I was in the exact same situation as you. I wanted to confirm that my seed phrase would properly restore my accounts if my Ledger were to get wiped, but I was too nervous to wipe my one and only ledger just in case for some reason it didn't work. When I got a second ledger that wast the PERFECT chance to test out the recovery. You'll set the new one up using the seed phrase you have written down, and in the end you'll end up with 2 ledgers with the exact same seed phrase inside of them. You could think of them like duplicates of one another, and could use them interchangeably since the accounts all generate from the same seed phrase.
Long story short, you should absolutely take advantage of the fact that you have a fresh Ledger to practice recovering from seed phrase. It made me feel a lot better when I proved to myself that it works just fine, and hopefully will do the same for you 🙂