Transfer file from Xiaomi Redmi 4A to Mac
Sorry didn't get your question initially because of "I'm not looking for non-USB solutions for this question." sentence.

As for Bluetooth solution - Open Mac->Settings->Bluetooth on your Mac, there will be checkbox "Show Bluetooth in menu", Bluetooth icon will appear near your clock in top right corner. Click it, there will be "Send files to device". Click it, choose file, choose your device. You transfered file from Mac to Phone.

As for reverse direction - open any File Explorer application on your phone (stock explorer, ES, whatever), select file you want to transfer, long tap it, select "Share", select "Bluetooth", select your Mac Bluetooth name. You done.

Sorry for my English and maybe not very accurate menu item names - I am Russian and have Russian Mac OS and Android.