The 'poisoned' converter won't cause any problems .. well not unless someone checks the pollution levels coming out the exhaust.
If you have a lambda sensor (some times called a CO2 sensor) that will also be killed by the lead. Best to pull it off the bike - place a bolt back into the exhaust to seal the hole and let the EFI run without it. Only put it back in when you have run a couple of tanks full of unleaded through the bike. They are not cheap items so best to save the replacement costs.
Regards Frank Warner
motorcycles BMW R80 G/S 1981, BMW K11LT 1993, BMW K75 G/S