My options would be, in this order.
1. Scrap if Urethane cannot be present,
2. Do a CTE comparison.  ICs and Resistors that have been thick coated with UR will typically not have any issues, chip capacitors, if they are large (0805 or larger), may be impacted.  Glass bodied parts will crack at the frit under thermal excursion if the UR coating is thicker than 3 mils.
3. If you can stand a mixed coating state, I would locally strip the UR away from any parts that would be sensitve to breakage and stay away from those that would lend themselves to entrapment, fragmenting or bridging.  Use URESOLVE 411. 
4. Urethane is primarily Xylene, and most strippers for Urethane are also high in Xylene, so the stripping process tends to thin the coating and make it run everywhere.
5. Silicone and Urethane have a love/hate relationship (they tend to make each other de-wet), so overcoating is not recommended unless you are only overcoating selected areas.