One note: it's always a good practice to show where a custom class comes from, like:
https://github.com/HanSolo/tilesfx
I couldn't find anything to bind to, but I did find two interesting properties:
autoScale and
keepAspect. You could either use the setters:
or maybe TileBuiler exposes the properties:
That last piece of code is a guess, so check it out first.
If all else fails, email the author.