I'm planning to use itch.io to host a game project for my internal testing group, eventually rolling it out to a larger closed beta via the refinery tools.

From the documentation, I assumed (perhaps mistakenly) that I could give my internal testers a download key and they would then be treated by the itch.io platform as having purchased the game normally.  However they still get the Buy Now button when they go to the game page, or when they read a devlog to which I have attached the game build.  As far as I can tell, the only way for them to download the latest build is through their My Library page.

Is this normal behaviour or am I missing something please?

Did you tick the "Download key can be claimed" checkbox when creating it? Should be the default in fact.

Hey, The layout of the project page doesn't change much when someone owns the project. We add a banner on the top with a link to their download page, but the product page is still purchasable if they scroll down. It's possible to buy more copies of games as gifts.