Thoughts

So basically, I do have long term plans for the kind of story I want to tell in terms of character development, of course. (plans that sometimes change a bit in response to things that happen, which is what I meant with developing them organically - not that I don't have plans and just go with the flow)
But my problem is that I want those plans to come from my, how do I put it, my sense of story? My storytelling ideas?
And not from the fact that I as a player want to use the shiny new equipment we have.
It doesn't actually matter how well we would be able to fit it in the story or how interesting it would be; to me would just feel wrong, like I was trying to shoehorn something into her story that doesn't really fit there.
(which might not be rational, but it's how it is)
Aside from that, the story is already rife with character development opportunities (and let's be honest, if I want more I can just poke you) that there's absolutely no need for my equipment to be one unless I want it to be one, in my view.
Which brings me to my last point - I think that, insofar possible, equipment should not really force character development to use it. Providing opportunities for it is great! But people should also be able to just use something because it's neat without having to shove in character change to do so. Providing a balance been story and mechanical diversity, as it were. Player freedom - provide opportunities, but not forcing them.
Take Saoirse - her insecurities fall squarely in her personality and how she interacts with people, but she's very confident in her skills (too much so, sometimes)
So, grasping at equipment as a reaction to failure is very unlikely for her because she's unlikely to blame herself in the first place.
(But such a situation like you stated would already be full of character development either way, so the equipment part wouldn't really add much anyway even if she would)

Anyway, just my (no doubt flawed) player perspective - I won't hold it against you whatever you decide, but it's probably interesting to know :)