I can provide more detail on the topic of US devices. Ultimately, Aqara determines which devices are included in the Aqara App for Homey. Historically, our focus has been primarily on the European market, so there wasn’t a pressing need to add support for devices based in the US or Asia. Both @TedTolboom and I have communicated to Aqara the importance of supporting these devices, though they remain somewhat hesitant.
Feel free to contact Aqara directly to express your interest in having these devices added! 
