Android lets you tinker with devices in a manner that no other mobile phone OS does, but to do this requires rooting phones and flashing custom ROMs, which is where recovery software like TWRP comes in.
From now henceforth, you can now flash custom ROMs on your Xiaomi Mi Note 3 and Motorola Moto E4 without any worries thanks to the official TWRP support these two have recently gained. Fans of the Mi Note 3, in particular, will be glad about this addition as they can finally get rid of the heavy MIUI skin in favor of a custom AOSP-based ROM like LineageOS.
To grab the TWRP recovery packages for these two phones, check out the links above. You should also find all the other necessary details in the respective links.