I'm looking to move Enterprise Architect source versioning provider from SVN to Mercurial. One unnoticed feature is to use SCC provider, instead of direct support within the EA.
To do that, an SCC provider needs to be configured first and then selected within the Enterprise Architect. Check the following links for the instructions on how to use SCC provider in EA and the SCC Provider for Mercurial.
Sergant's Home Page
From the Hg SCC Provider page, download this file. It is an older version of the provider, supporting MS SCCI API which is compatible with Source Safe and other software. The newer versions only support Visual Studio SCC Package API and is not recognized by Enterprise Architect.
Set your repository to Update on Pull and Push on Commit and the workflow is similar to the SVN one.