The last issue in the Migration Hell was Revit Server. To be precise, not the application itself, but the client authentification.
With all it’s bells-n-whistles, it lacks most part of the documentation. The application itself runs on IIS, uses Windows (NTLM) or Basic authentification, but nothing is said about the Revit client. The only thing you can find – you must login as domain member to use the Revit Server.

It’s not true. You should, but must not.

Two things must be done on the client to use Revit Server:

  1. authenticate in the domain and every server you will need to use. You must use your domain login credentials to authentificate. The AD domain uses trust relations to authentificate you in the domain servers. If you prefer not to login to AD domain, you must take care of it by yourself
  2. change environment variables.
    • %USERDOMAIN% point to the current domain, if logged as domain member. If not, it’s pointing to the computer name. Setting the variable to the domain name needed (eg. SET USERDOMAIN=MYCOMPANY) will do the job. You should not use DNS domain name, eg. MyCompany.COM, it’s set in %USERDNSDOMAIN% and is useless in the case of Revit Server
    • %USERNAME% must be set to your AD’s username, without AD prefix or FQDN suffix. Eg. if your AD domain login is mycompany.com\PerfectUser or PerfectUser@Mycompany.COM, use “SET USERNAME=PerfectUser”.

That’s all. Enjoy.

PS: if you use Local Revit Server, and Central Server is located somewere in the Other Domain, you will probably need to authentificate to the Central Revit Server too. Not sure about this.