I did not know about this device so I did a quick research: it's essentially an optimised version of early plasma devices that use instabilities to create a very compact, dense structure that can reach really high ion temperatures. The main problem I see is that this structure is very short-lived: on the order of 10 nanoseconds.

These devices existed for a long time and have been used as X rays or neutron sources but not for fusion power. LPP have explained the exact machanism at the basis of the DPF fusion and have optimised the radiation losses and electron heating to reach higher temperatures but from this to claiming viable fusion power is quite a stretch.

Lerner comes across as a bit of a nut. https://en.wikipedia.org/wiki/Eric_Lerner

The board of advisors doesn't have a single physicist on it -- makes me suspicious as well.

https://lppfusion.com/investing-in-lppfusion/our-plan-to-net...

Then there's this bit: "switching to pB11 fuel will give us a 100-fold increase in yield" -- compared to deuterium. That's straight-up backwards. pB11 power density is actually more like 100 times less. See https://en.wikipedia.org/wiki/Nuclear_fusion

Yes, he's published papers about his experiments, but there's nothing in them about how he's going to get to net energy output -- so that part is not peer reviewed.