Ah, in that case, it's a four - i do fail toes forward full squats, as without warmup my ankles are not flexible enough to allow a barefoot deep squat movement. I can perform the full squat without a hitch, it's just that my heels lift from the floor. lucky me.
would a bit of salsa dancing help fix the old internal rotation deficit?
It can be ankles, too. Although ankles vs hips can become like a chicken and egg argument. However with toes out you get a little more wiggle room with the ankles because you can allow your feet to cave in and flatten and take ROM that way. The point is really, if you can deep squat toes out but not toes straight forward, then you should look a little deeper and see what's going on (there may not be anything worth talking about going on, but it's a reason to look into it more) - this in in a nutshell is why I became more engrossed in the FMS. There's loads off assessments you can do on a client. You could spend the first few sessions doing assessments. So having a starting point and also a "road map" of sorts, especially for an over-thinker like me, is very valuable.
The hip internal rotation deficit was just an example of one of the things failing "toes forward" could lead to exposing.