Hey everyone, this is my first post here.

I am currently learning full CMLL with the help of Kian's resources (thank you; about 30 Algs in) and have a simple question about CMLL recognition.
How do you differentiate the two O cases (adjacent vs. diagonal swap) when the Headlights happen to be in the back?
At the moment, I am torn between:
1. Simply doing a U' and then checking left side. In case it is an adjacent swap, the headlights are then already in the correct position for the alg. In case it is a diagonal swap, I waste a move.
2. Checking whether both opposite stickers on the left and right are the same colour or not. If they are, i do the diagonal swap alg, if not I do U' into the adjacent swap alg. This never wastes moves, but takes me quite some time to check.
What do you do / think is faster in the long run? I am aware that already looking for corner orientation / permutation while doing SB is optimal, but I don't always manage to do that completely.
Thank you and have a great cubing day
Max