What ensures this? No one.
Last I checked the Pentagon 'lost' billions. Various agencies aren't rigorous with the taxpayer's money, also their time horizons seem skewed (very little R&D to reduce various costs internally).
Nor are they a fair actor. How could a single inventor petition the govt to pay up? Don't say a lawsuit because 'national security' supersedes any petition.
Nonetheless, my main point is none of the above. My main point is why would a worker/inventor have any right over a technology? Their job is funded by taxpayers. In business, the same is true. 'Work for hire' is the concept/term. I get that they are trying to modify this to returning some money to the people but...if 150k is the limit, will this be a new minimum wage? Or does this limit account for inflation? Honestly, highly skilled workers (mostly) know their value to the market. I think it's a poor use of taxpayers money to give a % of an invention. Fire the bosses, be more nimble, there are plenty of alternatives to this degradation entering the equation.