I have a Xiaomi Redmi 4G (codename: Dior) that is 3+ years old. It works on T-Mobile.
That chart is helpful. I would also read the reviews of the phone and check if the phone says "Global Edition" or "Global Version" to also check compatibility.
I use the Mokee ROM. It gets regular updates. But, the Huawei Ascend XT2 feels much faster with a longer-lasting battery.
https://www.frequencycheck.com/carrier-compatibility/p5vW4/a...
I thought they were mostly not useful for US carriers?