Will An Unlocked Note 10+ Flashed Withh ATT Firmware Retain All Exclusive Features?

[Android Central Question]

Hey guys, so I'm looking to take advantage of Samsung.clms current offers on the phone ($200 in accessories and 500 for a trade in) but the ATT vairent doesn't come in the blue color which I really covet. If I was to get the unlocked version of the phone, will flashing the ATT firrmware to the phone give me access to features like WiFi calling and VOLTE?

I had originally gotten my s10 unlocked and all those functions were missing, pretty odd to me as the Pixel 3 had them all