Never have disconnected any of my 12Vdc items except for the Chassis batteries.
never have a problem.
If a electrical item has a problem then it would go bad even at 14.6 Vdc.
Remember car radios? Especially when the alternator would go bad and put out up to 18Vdc? Nothing happen to the electrical system.
I remember the my days of audio/TV repair shops. We used variable power supplies, to test everything. We would go up to 18 - 20 volts. without a problem.
All electronic devices have a internal regulator. This regulator keeps the input voltage from damaging the components.