...OK two items here.
First of all, Fab III While I know what it effectively does (from 3E) other then some mention and the cost in Street Grimoire I can find no other information on how it works in 5E. Primarily, there is now a Force Rating assigned against which the base cost is multiplied against per each 1 cubic metre unit. What does the force rating actually relate to?
Next are Thermobaric weapons. I have a character who came into possession of an FAE bomb. but can find no mention on how to gauge it's total yield. Again in 3E this was spelled out pretty directly based on the liquid measure of the device. The closest I can find to this in 5E is the atomiser, but by it's description it seems more like a "room fogger" that fills an area with an explosive mist which is then detonated rather than a device that is air dropped and has a dual trigger: one to create a large airborne cloud of misted fuel and the other to ignite that cloud to create a massive shockwave (hence why it is sometimes referred to as the "poor man's nuke").
The size is a standard 208 L drum, so not sure how to treat this.