Once Nico had the array set up all around the room, she started to create the first structural pieces of a much smaller Mecha. Either it was a scale prototype, or she was going to build a Line Mecha-sized variant first to test the changes to basic systems before she implemented them into a larger Mecha.
Not everything would scale well, but if it didn't work at Line Mecha sized, the chances that it would start to work once it got to Super Heavy or Titan Class sized was incredibly small.
She started with the basic skeletal structure, made of the Monomolecular material she had been building ships out of, and which the Arisen used for many of their constructs. Their version wasn't exactly the same, but it was similar enough for Max to call them the same category of materials, at least.