Procedural scratches node

All surfaces have imperfections and scratches is almost always present on any material, yet I have found no good procedural way to do this in corona. Siger Scratches is barely usable and I have gotten no good results from it whatsoever, and bitmaps allow for no customization.

FStorm is a good benchmark for procedural scratches that is easy to use but it only produces straight scratches whereas in reality they're almost always bent. A similar solution as fstorm but with the addition to bend scratches would be very useful in corona.

(Also if you could figure out a way to speed up rendering of micro bumps (like car paint swirl scratches) that'd be a huge bonus because I currently find it painfully slow, at least when using bitmaps for tiny scratches.