DesignToolBox Install notes
To install DesignToolBox under multiple 3ds Max versions
Run the installer each time choosing the corresponding 3ds max installation folder. Opt-out when the installer prompts to uninstall previous version.
Uninstall
When you want to uninstall the tool, the installer will only remove the last iteration. The procedure in this case is to re-install the plugin in the 3ds Max version you want to remove it, and then uninstall again.