No... Sorry to make it confusing. The dealer either gets a one-time $150 in cash from KMF by using the lower Money Factor, or they make about $250- $300 by using the higher Money Factor via the deal (and not getting $150 from KMF).
Hope that helps. In other words, the .0004 is only going to add a few hundred to your 36 months overall.
Oh, and as for your second question: 2nd question, do these lease incentives "get better" the closer to the end of the 2month window?
No. At least not so far. For the Stinger, KMF has provided a static two-month Leash and Cash + Finance incentive sheet. It doesn't change at all for two months straight. KMF could change things whenever they want I'm sure, but so far it's been very stable.
NOTE: Today I saw an article headline (but the link wasn't working...) regarding Stinger sales slowing... If that has ANY validity to it, then I would expect May and June's new rates and offers to be slightly more aggressive. If not, they'll stay nearly static with only slight changes... After all, we are heading into summer now, when car sales should pick up and so should Stinger sales.
I suspect the best deals we are going to see for the 2018 Stinger's will arrive for the September-October months, when the 2019's will be about to roll in and factories need to keep moving along and producing.