In the same situation as well but those adapters require you to plug that ground wire into an outlet or something. Seems scary or prone to failure to me.
There is a dryer outlet splitter you can get from SplitVolt / Amazon that comes with a 10-30 and a 14-50 outlet. The only issue with this is that you will have to limit your charging from the Tesla to 24amp since thats the max the 10-30 outlet would support.
I have also read somewhere that you could order the 10-30 cable directly from a Tesla Service Center. I’d recommend giving that a shot.