I'm not sure I understand what you mean by this. Do you want to check whether the package installed correctly (i.e. that the install scripts aren't broken)? Or do you just want to make sure that some page of a package is not throwing a Request Error?
Automated testing is generally meant for testing the Tcl API, not so much the logic of individual pages. TclWebTest should be for individual pages (disclaimer: haven't used TclWebTest and don't know much about it).
One way to get around it, of course, is to put the logic into a Tcl API, which is considered best-practice anyway.
But please let me know what is you mean by "checking the front page of a module".