Interactive Height Settings for Templates

So far, you will have to input numbers then export to be able to see how the template goes. I met a client who was very picky about font size and adjusting the height template by number was a big hassle for me. If it's possible to set a preview on all the lines like ascender, descender, cap height, x height, whatever it is, it will help alot. Bonus point if it can be adjustable like in the image