Yes, always play dual-class, so to say. For every pair of important fields X and Y, there are numerous people who can do X very well but can't do any Y, and vice versa. If you do both X and Y well enough, you are at a huge advantage.

Trivially, being good at frontend coding and at UX design (cognitive aspects, etc) helps. Being good at designing software and being good at talking the language of your business is super helpful, this what's required at the director / VP Eng level.

And yes, do take the math. After just 2 years of university math (as an embedded systems major, I had to later study myself to grab some missing algebra, some category theory, etc, to grasp SICP on one hand, and Haskell on another. This helped me become seriously better at writing and understanding code in industrial languages.