That is precisely what I have been doing.
A typical example I will give you is this.
Yootheme Joomla Demo Template packages comes bundled with a Joomla installation files in it and requires that it should be installed from its own folder. Now Softaculous comes with a Joomla installation of its own. So the question is, how can I navigate through AMPPS to install the particular Joomla installation that comes with the template demo package, thereby by-passing the Joomla script that comes with Softaculous AMPPS?
Without my doing it that way, I can see and use the Demo package of the template.
Mind you, I have tried installing the Demo package through Joomla-Extentions-Template Manager. It actually installs but I cannot see it in the Template manager to make as default, and when I install the empty template, it installs but I cannot see the demo files in them.