In what area(s) would you say you are most lacking?
If you were to coach/mentor someone, would you have both the ability to give them the knowledge and support they need, as well as the technical understanding to give it all grounding? If not, that is what I would focus on.
For myself I try to give myself half a day a week on self-development, and recently I’ve been wanting to improve my communication and presentations skills. Otherwise, no matter what I know, if I can’t express that information in a way that others will understand, or seem unapproachable so no-one wants to come to me for my information, it is all for nothing.
One thought I do have in your circumstance is, how much will you use your technical skills as a manager? How hands-on will you be (or even, can you be)? Where I am, managers don’t test, and it is more around resource management, support, those kind of tasks. They can be approached for how to go about an action, but more in a way of the tester covering themselves if something were to go wrong, or just so the manager is aware of what is going on.
If you are in a similar situation, than the more managerial skills will be useful. If you don’t know those technical skills, would you know who to approach within your team and get that knowledge to the person(s) who need it?