It appears Lotharek is taking preorders for a small batch of Incognito boards.
https://lotharek.pl/productdetail.php?id=276 this version has the FJC firmware already flashed and part of the added price goes direct to Jon. I would recommend this version as the functionality is much improved and a far superior experience.
https://lotharek.pl/productdetail.php?id=275 this version is the original firmware by Candle, slightly cheaper but not as functional.
that's a version 1 board, it requires an update before the flash method will work, it also requires resistors to be added during install... when we here this sort of thing it's what immediately pops into our minds.
The procedures and fixes are posted, so quick search using the improved search function of AtariAge should get you all the info to do both :)