There's literally no difference in using MAS over using a key.
In fact using MAS is better as it activates using your HWID which means once you activate using MAS the next time you install the same edition of Windows (like Pro), you don't need to enter any key and you'll be activated as soon as you go online.
It's not a local persistent software, it works using Microsoft's activation servers.
And if anyone still doesn't trust it, disconnect all your storage devices and just have one spare SSD/HDD to install your current edition of Windows and activate using MAS once.
Then reinstall your devices and boot. Use a Retail generic key for your edition from here: https://www.elevenforum.com/t/generic-product-keys-to-install-or-upgrade-windows-11-editions.3713/
and you'll be activated.
