Hello, sorry for the late reply.
Typemock Isolator includes a command line runner, TMockRunner.exe, that allows running tests with Isolator enabled.
You can run the tests with MSTest using the Execute Program task in Final Builder. In the program file, specify the file TMockRunner.exe, which is located in the Typemock Isolator installation directory. As the parameter, specify the command:
mstest.exe /testcontainer:<yourtestassembly>
So that together it executes:
TMockRunner.exe mstest.exe /testcontainer:<yourtestassembly>
(make sure to specify the correct full paths to the files)