What version of testnet is launched with the executable included in Bitcoin Knots?
Im not logged right now into my node computer but I think on the bins folder there was a bitcoin-test or something like that executable which I assume launches Knots in testnet mode. My question is, does it use testnet3 or testnet4 by default?

I want to enable testnet4. What is the size of testnet4? I will launch in pruned mode. I just want to test some transactions to practice with airgap setup, and learn how PSBT works without risking real coins. So I need to sync tesnet4 in the laptop for the node, and then create a new testnet wallet on the airgap wallet. But I don't know if it will launch tesnet3 or 4 by default. From what I've read testnet 4 is better and faster to sync since chain is smaller.

Anything else I should consider for this?