the oil you have MIGHT be ok. Check it out. The limitations were primarily aimed at 10W-30 as it was used in the cars with catalytic converters (the source of the issue). 20W-50 may not have been impacted and thus might have sufficient levels of zinc and so on.
You may well be able to find the levels online.
20W-50 for classic motorcycles like Hondas and so on comes to mind as good. Valvoline 20W-50 Racing Oil.
If you send me a PM with your regular email address, I will send some notes I took years back from some oil guy on
a car program that went in to specific levels need for flat tappet motors.