You have a few options for a left kick, a quick stance switch, stepping forward at 45 degrees, or throwing it straight off the ground (whip kick), or simply switching to southpaw for a moment and fighting from there.
That's alot of options, use them to your advantage
Oh and as far as telegraphing the switch....c'mon now anything can be telegraphed if u aint doing it right.
If you are any goddamn good at the kick, the switch will be lightning quick and you'll kick as soon as you switch, one fluid motion.
Just don't telegraph the switch is all, keep your head at the same level, keep your shoulders and hands where they are.. With alot of Thai boxers you don't even notice the switch until it's too late.
There ya go, very little telegraphing.
That being said, i only throw a naked switch kick to mix things up. If i'm gonna switch kick it's usually after a punch or as a counter.
EDIT: Oh yeah, STAY IN RHYTHM, you're opponent is bound to know your gonna kick if you pause and give him the chuck liddel eyes to set up. Dead give away. Work the switch into your fight rhythm.