> I enjoy mentoring and explaining things, writing docs, and being involved in design of systems and influencing technical strategy

One of the great dilemmas is that these things are always interwoven with the non-technical aspects of being a manager. There is some aspect in which it is essential - "how long will this work take" depends intimately on the technical complexity, exactly how skilled the available resources are in the necessary areas etc. Other aspects are completely non-essential - "responsibility for staff completing health and safety training lies with line management". I would really like to see a model where these are disentangled.