There is no check to ensure a single home directory has been configured in confluence-init.properties file.
Having multiple home directories, such as:

confluence.home=/Users/User1/Desktop/standalones/data1

and

confluence.home=/Users/User1/Desktop/standalones/data2

Confluence will consider the last "confluence.home" value to configure <Confluence-Home>. All entries prior to that will be ignored.

This could cause Confluence to upgrade/downgrade unknowingly, if the last entry corresponds to an older home directory.

Apart for checking for the presence of a home directory, it will be safer to also check for multiple home directories.