They haven't fixed anything yet, but I got a sincere sounding apology from the director of Software Heritage. It's a start!
I am no longer being deadnamed on Software Heritage Archive's copies of ftfy, my most popular open source package.
They took down all the deadnamey copies of it and left just my official one, plus an OpenSUSE package that is up-to-date enough to have my correct name. (OpenSUSE is a thing that's still updated??)
I won't consider this a victory until they document the process so another trans software author can use it, and that process works without anyone having to email all their personal information to the bureaucrat from hell. I've got some other code I'll need to apply the process to, so I can see how that goes.