High quality USB-PD wall warts without Y caps, double shielded transformer core and extra wide gap isolated transformer secondary windings exist, even without even a GND pin and they have full approvals. But if you want the full 60 watts, you need an PD negotiating IC to receive the 20v, otherwise you are stuck with 5v, 2amp. On the up side, if you gone through the trouble, now your device is also compatible with USBPD power packs.