(messy notes ahead)

I used Tor browser only for this test. First: captcha is VERY annoying.
I have to agree with Terms and Conditions. I can't open them in a new tab (my favourite middle mouse button), but instead it opens in a small popup screen. It's on 80% zoom and if I make it larger, the text doesn't fit anymore. I don't have a big screen to read post-it size PDFs.
After reading the first PDF, my captcha expired already. I think I had to go through a total of 5 captchas before I had a working account.

Without reading anything, I jump to Create Offer: Sell 0.1 BTC for XMR:
Try again for 0.01 BTC: that works. After I deposit 0.01 (testnet4 to be clear), it keeps counting down from 60 minutes to zero. At this point it would be nice if it detects the deposit. I clicked "Confirm deposit" and now I wait.

I don't like the default Notification settings: I don't need that many emails for anything that happens. The default should be off for everything, so I turned it all off.

For now, I'm waiting for a confirmation, but none of the other offers include BTC and XMR on testnet. Those are the only 2 testnet wallets I setup on my computer, so I can't test any of them now.
I checked other offers, and the first thing I noticed is that "max exchange amount" can't be clicked. It should be clickable to easily buy that offer.

This sounds decentralized, and I did send 0.01 (t)BTC to your address (tb1qvt3m9trgpw9dlp0su0ca2nctwdxdy6fyqrqsl4), but how can I possibly check if that's not just an address under your direct control? It looks like a normal testnet address.

Update:
I'm starting to think you're mixing up testnet3 and testnet4: your Beta guide linked to several testnet4 faucets, which made me think that's what you're using, but other parts of the guide make it look like you're using the old testnet. You should probably use the most recent version, which is much easier to get.

No-KYC means you also won't get my IP-address, so I'm not going to stop using Tor.

Maybe you can expedite this as a privacy feature

Maybe a different captcha can work, Protonmail has a much easier one (for humans).

I don't like installing unknown software, and I don't want them on my system without VM. But as I never use those coins, I'll just skip them.

This is a BIG problem! You're basically asking users to trust you (to be semi-decentralized). Now it looks like a regular website, but with the additional risk of losing coins because of a bad smart contract.

All I see is an address. I can't see when it was created, and even if it was just fresly created, it could come from a regular wallet.
This is one of the reasons I've never used "decentralized" exchanges: when it comes to the details, I can't verify but have to trust. I'm not in crypto to trust people, and I've seen enough reasons not to trust anyone.

So which one do you use: testnet 3 or 4? My deposit didn't show up (and I'd love to see what your sending transaction looks like when you send it to someone else after I exchange some for Monero testnet).

I took one of those offers, and made another deposit on the latest testnet chain. Let's see....

My post was kinda "work in progress", hence the "messy notes ahead". I'll just quote myself there.