I managed to customize the app_offline.htm and keep it in my Visual Studio Project in the root folder. I figured out that when I publish the ASP.Net project my customized app_offline.htm is used instead of the automatically generated file. That works perfect. But in my local development environment I don't want IIS to serve this file all the time. But I also don't want to rename the app_offline.htm to app_offline.xxx every time I'm publishing.
Is there a way to disable the app_offline.htm behavior on my development machine?