Canadian Variant S21, S21+ and ultra S21 has MST if you look at the newsroom in Canada. Only Variant doesn't have it in the US. Even though US S21 lost it function. Co-founder got patent back and start campaign and create OV-Valet. Key FOB supports MST with NFC for us consumer and releasing in April and massive producing right now.
I found info on Saturday and lazy to post. I rather answer people question and less headache. Give thumbs up to Samsung ads on Facebook and trying to upselling me Galaxy tab active 3 that is where I found it.