It can be used, but if you use A 120W A-port charger, the charging speed is not as fast as the 20W C-port charger. If you use the above two chargers to charge the Apple x, the maximum power is only 12W, because the PD fast charge of the Apple x requires a C-port charger.
If you use a 120W C-port charger, the charging speed of the off-screen state is exactly the same as that of the 20W C-port charger, and the bright screen charging (while charging), if you ensure that the body is not hot, it may be slightly faster than the 20W C-port charger