Way to Test Custom Codes

I can't tell you how many times I've made a custom only to find out that, hey, surprise; once made, their code doesn't translate onto future generations well at all. This is regardless of the fact that the code is 100% passable, but rather it, if it is a glitch, glitches out to unmarketable insanity.

I suggest that there be a tool where the user can input their design's code (white full 100%, black full 100%, etc.) into a system like the existing Pup Predictor. Then this will spew out Custom Pup Predictor images, letting you know before you waste 8-16 bones on a new custom if its code will produce likeable characteristics for the next generation or not.