I just converted my latest refractainstaller-gui from zenity to yad, and it appears to work. Did a single-partition install with no extra options checked. I need to make a few other changes (not related to yad) and still need to work in the code for putting the bootloader into a partition. Will probably get it done and wrapped up into debs this weekend.
I like yad a lot. I especially like being able to have more than two buttons in a window. I'm adding an Exit button to several windows, so you will be able to abort the installation a lot easier.