I think you can stop it short of the switch.

I would move the switch over to the left.

I would move it to the right. It would look better in the backsplash field.

I’d tile to the outer edge of the cabinet that’s beneath the countertop.

With this pic, I'd say green line, but a pic of the whole space from further would give a better perspective and you'd get better advice. I'm not a fan of stopping tile at what is already a strong horizontal line (usually the undercab line but here under your floating shelf. It's often better to take the tile up a few rows. However, it is hard to tell if this would work from the little bit shown in the pic.

I have a similar situation, and the tile was taken all the way to the door frame and floor. Waiting for the five tiles we were short to finish to lower section. oops. also not yet grouted.

I would stop at the shelf edge personally

run the red line under the shelf all the way to door trim and down to floor as in the green kitchen above. especially w the tile being a neutral color. there is no point weaving around a switch cover or leaving 8 inches undone over toward door trim. the 8 inches is small enough this will be cohesive and without confusion whether the "wall itself " is being tiled...its just an extension really..... and will make it a smoother look.

I hadn’t noticed before, but the edge of the shelf runs parallel with the lower cabinet if that influences any opinions.

In that case, I'd stop it at the edge of the shelf.

ETA: really like your shelves and placement.