That would not work for me very well. I have i. e. about 150 handwriting fonts in one folder and would like to be able to go through them (and only them) in order to then decide which one I want to use and to install. The same is the case for other types of fonts. A font viewer for not installed fonts would be much better.
Really funny. I just found out that I can view these fonts with the ordinary preview function (space bar) that is built into OS X. An application that shows several not installed fonts at the same time in a list to compare them would be better but this is already quite ok.
I do use FontExplorer Pro but as far as I know it cannot be used to view not installed fonts.
I could, of course, create a set "Handwriting Fonts" here and then install all my handwriting fonts in it. But it would mean that I have to install more than 150 fonts of which I will not use more than one or two, and these fonts will then be scattered all over the various alphabetic FontExplorer font folders.
I think for selecting fonts to be installed nothing could beat an application that can view not installed fonts, especially if the sample text can be defined by the user. Strange that such an application seems not to exist (anymore).