When using TC/TE in shared mode, script Extension files are locked by each active instance of TE and / or TC. It would be better if TC/TE would just at each start of a test run check for Script E...
Again, another strike against shared mode for execution. If you're not using shared mode and your script extensions are local to the machine running the test, this is not an issue.
Again, shared mode seems best for a small development team and for development environments only... test execution should be done using a local, dedicated copy of the project being executed.