Warm congratulations on the lovely Mageia 3 release! It installed beautifully, and it's running very well here.
Perhaps the only irritation was having to type space after the ' key to get an apostrophe, so I was glad to see this post and have been testing out system settings. I'm fairly sure I'd chosen standard US keyboard layout during installation (I have an 84-key Filco keyboard, with US layout), but System settings > Input devices > keyboard showed me US intl was installed. I added plain US and switched to that - bingo, back to the usual one-key way to type an apostrophe.
But it's interesting to see all the other options. I sometimes want to type a £ sign, and look! now I can. I've ditched the US intl layout and added English UK as my second option, with € and £ signs ready. That's better than having plain US and US intl, since the label and flag for these are the same - tricky to tell which one is active

Has anyone else found that US layout chosen during installation became US intl?
Thanks for pointing me in the right direction.
Mageia 8 for x86_64, Asus ROG Strix X570-E, Ryzen 7 Octa-core 3700X, Sapphire Radeon Pulse RX 5700, 32 GB RAM