When the Legendary Mantis Blades are installed why am I not seeing an option for a 3rd Mod?
The Blade Edge and Rotor Mods are showing up, are there other Mods for them I haven't found or are the regular Blade Mods supposed to be showing up when I click that empty Mod spot on the Mantis Blades?

I also saw somewhere online that Ripper Docs sell Mods Crafting diagrams. So far after 2 playthroughs I have not found a single Doc that sells diagrams.