unfortunately it's not setup to have the usergroups switched around like that, didn't take that into account when I created it. I'll work on a new version to fix that this weekend.
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I just released 1.4.1. It adds 3 usergroup selection boxes to the acp options section. One for site owner, one for admin and one for moderators. I installed it on here, you can see Fillip H. and Cosmic are now displayed as site owners, I am displayed as Developer (I switched the text on this site from Administrator to Developer).