Custom Properties Not Working When Hidden

I'm trying to setup custom properties and have them as hidden by default so that they are set, available, but not seen and cluttering up my items. An example would be tax. I have a custom property for Tax that is set at the default value of 7.25 at the project level and then inherits down to all levels below. This works great as long as hidden by default is not checked. As soon as I check Hidden by default and use this template, the default value does not populate, and all things set to inherit revert back to number with no value.