looks better with each iteration keep going! as for substance designer, have you seen this? https://www.allegorithmic.com/blog/your-smartphone-material-scanner
No. Large amount of time spent does not = convoluted In fact it can be the inverse ;) Things are simplified and streamlined over time and iterations. Most definitely true.
Nore retail hell receipt paper scribbles. And this, started as a study and wandered a bit - (first iteration -- has its own merits, but is weaker overall)
echoing what vig said, it's jumped out on every iteration of the image : where IS that shaft of light coming from? There's nothing solid above to form it