microwave cracking?

OK, the WVO crowd is pretty large, and on this forum pretty low profile, so how about the cracking guys and gals?

Recently, a friend mentioned that he would like to start playing with microwave fuel cracking from waste motor oil. I have strongly discouraged him from directly using WMO in the past, and made my beliefs in the order of priority of resource use putting cracking (recycling) far below resource recovery (re-refining to capture lube base stocks). But, the market for re-formulated motor oils seems to be slipping away so maybe cracking to fuel makes sense???

https://core.ac.uk/download/pdf/77408248.pdf

I have made atmospheric distilled overhead products into motor fuel when experimenting with building thin film evaporator(s) for base oil vacuum distillation, but never played with thermal cracking as the pressures and temps can be dangerously high and the carbon fouling a bit of a chore (I think that contracts to bit..ch) to clean out regularly.

I'm pretty sure the guys that pick up the waste oil where I work are doing cracking into fuel rather than any sort of lube oil stuff. Just selling it as crude oil more or less, as with modern cracking that's what it can be.

Interested to see where this goes, been running waste ATF thinned with gasoline in my IDIs for years now. Never looked too far into how hydrocarbon cracking works