https://gbatemp.net/threads/ctr_red...for-old3ds-and-2ds.493736/page-5#post-8296304
This might be what Sono was referring to (though it definitely is just a slight mod to his own redshift implementation). It doesn't actually apply the screen config at boot time but the option is at the top of the Rosalina menu so it can be selected easily with eyes closed.
It might be possible to build another Luma boot.firm that applies the screen config on boot (as early as is feasible in the code), but I'm not very experienced and haven't looked into it. You could then load a Luma "NightMode" with a keycombo through FastBoot, which would be pretty cool ^^. And perhaps with some work it could also load a chosen dark colour home menu theme...