That is great advice. A coworker of mine said he heard a speaker at this year’s expo say not to expect to get better climbing on someone else’s dime and to rec climb as much as possible. +1 on the short simple trees approach. Listen to your mentor, trust them and do what they say.Having climbing experience is helpful for ground workers.
Get some climbing experience, if only rec climbing, to have the aerial perspective and understanding, and continue working on the ground, if you like. You will be better on the ground. More valuable, more marketable.
Become an aspiring climber at any level, and become more valuable and marketable, but don't expect to get a lot of climbing time at work. Rec climb more, watch at work, ask questions, rec climb more, watch at work, ask questions, ask for an opportunity to climb when feasible. You will only want short, simple trees to start working. Small bites so you don't choke...you can eat an elephant that way.