Hi there. Currently the extension suggests the following setting:
'addpersonalurls-userpages' => 'Special:PrefixIndex?prefix=$username&namespace=2'
If you have a user "user" and another user "user-test", then the first user will see all pages of both users. I suggest to change the setting to
'addpersonalurls-userpages' => 'Special:PrefixIndex?prefix=$username/&namespace=2'