Biostructure Tricks:When you are modifying a chassis with the "Instincts" version of BIOY 273, you can choose to implant a single trick, as can be taught to an animal through the Handle Animal skill. Once you've done so, anyone (including the Chassis themselves) can trigger that instinctive trait with a DC 20 Handle Animal check (a sentient Chassis can instead use a DC 10 Intelligence check to the same result.)
In addition, the following tricks may only be instinctively coded into a Chassis, and cannot be taught to animals. These unique tricks require a heal check equal to or greater than the Heal check that originally created the creature to apply.
Nascent Form: A Chassis embedded with this trick can, as a full-round action, convert it's body back into Biostructure. While in this state, it can take no actions, except for a full-round action to convert back into a Chassis. However, in this state, it regains the fast healing that a piece of unmodified biostructure has.
Socket-Mind Implantation: A Chassis embedded with this trick must also have either the Circuited or Sentience versions of BIOY 273 applied to it. If it does, it may, as an action taking one minute, switch which of the two versions is applied to it (a Sentient Chassis could convert itself into a Circuited Chassis, and vice-versa.)
This is a very rudimentary foundation for this concept; it's intended to show that a little bit of versatility can be shoved into biostructure...