I would like to run HDI on demand and not have it continuously running in the background. If the program is disabled in the the autoruns list, it reports no drives found when you try and run it later.

Since drives usually fail slowly, there's no need to have something running all the time in the background. If it does fail catastrophically suddenly, it's too late anyway.

This would also make it easier to have a portable version that doesn't require installation as others have suggested.