I want to know if I can connect a single Pokemon Go account to 2 different Let's Go! games so I can only Use one of my emails for Pokemon Go.
But both games should not be close to the phone at the same time as that causes bugs. It's best to always unpair your game once you're finished to avoid device detection/pairing bugs*.
Note: The same applies to if there are multiple Switches/Go Plus/Go!tcha paired to a single phone or if multiple phones are paired to a single Switch/Go Plus/Go!tcha.
*It's likely because of the way Bluetooth works; status-bydesign.