Clearfont3 is still only alpha release quality. It has caused crashes for me on a few occasions as well. If you are uncomfortable with potential game crashes, you should not be using alpha releases. If you are comfortable with the crashes, please continue to use it and post tickets describing the situation on the project's page.
I use a lot of addons in the earlier stage of release and I dont mind to test but with that one there is honnestly no way to test anything at least for me.
I am not very fond of addons without any config gui, where I have to relay only on my chat window, not for lazyness but mainly because of my eyes and my memory (even if I can feel 17 playing WOW sometimes, bones and flesh and eyes remind me that well I am not so young :p).
So I guess I will just stay with CF2 for now and/or bypass some addons fonts by changing them directly in the .lua addons.