Please stop ranting about Elliot being a diversity hire. He joined google at about the same time I did. In those days there were no diversity hires at all or even a diversity policy. You were hired on technical merit, nothing else. (Diversity hiring started at least 5 years later, or more).
You could be bat shit crazy and be hired. As long as you passe the techincal bar.
Elliot has seriously good technical skills or else he would not have been hired in 2007/2008.
Do not conflate your dislike with the person with the skill of the person.
That said, he IS an incredibly toxic and disruptive person to have on any team. He is stubborn and vindictive. If you have robust discussions with him he will take it as a personal insult and go after you.
Do I know Elliot? Not really. Have I met Elliot? Many times in engineering meetings. I did not report to him, neither did he report to me. We belonged to two completely different reporting structures That said we did meet in technical meetings quite some times. (I would feel offended if you would show him a picture of me and he would not immediately be able to tell you my name. But no, we did not work together.)
Elliots problem is not his technical skills, he is skilled, that is not in doubt. The problem is his personality. Anything, the slightest issue, and he takes it as a personal attack. He also seems to feel like it is his job to correct any grievances that anyone ever have had in the workplace. With maximum force and maximum hostility and zero forgiveness or allowance to correct.
None of this have even anything to do with him being trans. Him being trans is the least of the issues with him in a workplace.
His problem is not knowing when to back off. You can have technical discussions and disagreements but eventually you really need to make a decision, be it right or wrong, but you have to make a decision on the path forward. Elliot can not deal with that. If he thinks it is the wrong decision, he will refuse it and protest and work against it. He will make it his life goal to work against what you agreed on and try to undermine it.
There is nothing like normal people "ok, we made a decision, I didn't like it but here we are and now we all have to work towards the agreed goal". No, Elliot is 100% my way or the highway and if you disagree I will try to destroy you.
In one sense it is really sad. A talent like that just going to waste because of insecurity and mental illness.
Would I hire him to my tiny contracting stint? No. He is sure skilled enough but I would not want him because it would just be drama after drama.
