LR uses the registry key to determine what PS to start up with Edit In.
Adding another PS version as an external editor causes LR to render a TIF or PSD on the way into PS. That may be fine or may not be what the OP is wanting.
LR uses the registry key to determine what PS to start up with Edit In.
Adding another PS version as an external editor causes LR to render a TIF or PSD on the way into PS. That may be fine or may not be what the OP is wanting.