No problem, glad to help. No credit is needed at all, although if you get to work with this, do give me a heads-up. I love your work, and wouldn't want to miss it.
An example of "Federalist tyranny" would be a very powerful argument against any future efforts to centralise things. The easiest way to fit that in (and to make it obviously perceived as a bad thing) would be to have Hamilton attempt a coup after he fails to get his way at the Convention. The coup fails, the conspirators get tried for treason, and Hamilton's viewpoints are deeply discredited.
Of course, I'm not sure at all whether he'd be reckless/stupid/angry enough to attempt such a thing. I'm fornd of vibrant decentralism (lots of diversity and localism, yay!), so it's easy for me to portray Hamilton as the bad guy. In reality, even if I don't agree with a lot of his ideas, he was an honourable man dedicated to his country.
An alternative to a coup would be to have the most Federalist states in the North-East (considering the period, I'm looking at New York and Massachusetts here) refuse to ratify the revised Articles, instead seceding and setting up their own Union. Around the time of the Convention, this would likely involve annexing independent-minded Rhode Island and the Vermont Republic by force. I'm not all sure a Jeffersonian USA could or would fight to get the North-East back (Jefferson was a proponent of secession in OTL, and going to war to liberate Rhode Island and Vermont seems unlikely). This situation would create a very decentralist rump-USA with a more centralist, historically hostile neighbour right next door. This makes for an interesting contrast-and-compare, allowing one to explore the notion of a very decentralist and a very centralist alt-USA at the same time. I'm not at all sure it would fit with what
@ToixStory has in mind, though.
(One thing that can be said, though, is that in such a scenario it would be interesting to avoid doing a retread of
Decades of Darkness. With a lot more of OTL's Union states within the rump USA, we should be able to avoid turning it into just a very powerful CSA expy. No doubt slavery in the slave states would go largely unchallenged in this rump USA, but at the same time, that could also avoid OTL's overly defensive tying-together of slavery with Southern identity. Perspectives abound for a contrast study between the two American union, both with their own unique good and bad qualities.)