Proof of concept?
If there were really a large pool of interested female software/hardware engineers going un/underemployed because of some pervasive "bro" bias, you would think that someone could pretty easily start a company aimed at hiring these folks, and end up with a superior staff at a lower price.
As far as I know, this simple proof-of-concept of the existence of a problem hasn't been done, which naturally brings into question the very existence of such a problem.
I don't understand the idea that every company or other sub-grouping of society needs to match the population structure of society in general. There doesn't seem to be any societal advantage in it, and it would certainly be very disruptive to society if half or more of all our companies, nonprofits, sports teams, etc had to be totally reorganized to reflect some sort of "social justice" employment quotas.