Do you need full full-size?
While complete 104-108 key is not super common in the fully custom space, finding a nice 1800 or similar is not as hard. Kbdfans runs the Odin at the high end, and they have its FRL sibling in stock now. There’s also the Brutal V2 from CannonKeys. It’s sold out in alumnium, but RNDKeys does the “Boston,” a compact battleship thet adds an extra row of function keys to a full 1800 layout. The 3D printed one is probably not “endgame” in the traditional sense. Then there are the occasional group buys like the Wind X98 or the Austin.
Below that, the Halo 96 from Nuphy is well regarded. Monsgeek M2 as well. The FC980 has various custom mods floating around the aftermarket as well. This thread is getting a little older, but there’s good ideas there.