No point to obfuscate KYC Bitcoin if they are American/jurisdiction with tax liability, you will have potential trouble down the road when selling back with KYC and paying taxes.
If they really want to scan their face for purchases they could buy a different crypto currency and withdraw to self custody and use a KYC free swap service. Though make sure to use a VPN or Tor.
nostr:nprofile1qqsgwj2rmdtuy3q572yj7y38sxlzr86usjck02merrevurvnn86yqncpr9mhxue69uhhyetvv9ujuumwdae8gtnnda3kjctv9uzdmpld is good for this. Pick a non-BTC crypto that stack supports. Buy it on Exchange withdraw to Stack Wallet then use Stack Wallets inbuilt swap services to get Bitcoin.