I don't thing I completely agree with the "role-model" effect you are describing. There are women like.

https://en.wikipedia.org/wiki/Ada_Lovelace https://en.wikipedia.org/wiki/Grace_Hopper https://en.wikipedia.org/wiki/Limor_Fried https://en.wikipedia.org/wiki/Jeri_Ellsworth

And many more. If these women aren't role models enough, how is me investing multitudes more of effort and hiring one or two female engineers at a small startup going to create role-models.

I believe in investing in the egg as you call it, by getting women interested in tech at a young age, we can have more candidates to choose from and then not have to jump through all the efforts and hoops this website want's me to do. I see no practical reason to reword all my job postings and hire a female-centric recruiter when I can just hop on angellist for an hour.