There is no discernable difference between booting atmosphère through fusée and Hekate. The "Hekate is broken" meme comes from a dev's personal vendetta who disabled his software when it would detect a hekate-specific file. Just keep your shit...
Gosh, so much corporate ass-licking in one single post... Once again I don't wanna write an essay but just ask yourself where that "entitlement" comes from, and maybe you'll have a clue.
It is, at least somewhat. The Tegra checks for the correct partition UUID. Thankfully it doesn't check for eMMC serial number/make though, therefore the GUID on a new eMMC can be overwritten with the old value.