Frame perimeter "minor protrusions"?

[WarehouseCrew]

Can someone help me understand the frame perimeter rule (eg. "minor protrusions" under 1/4" under R01-2)?

Our robot will be using C channel. We will have a lower level frame for mounting wheels and directly above an upper frame (also C channel) for mounting bumper, manipulator, etc.

1. Gusset plate - Would a gusset plate (1/16" steel) and bolt head that combined are less than 1/4" be legal according rule R01-2? We would like to use steel gusset plates on the exterior of our frame to create a rigid connection between the lower and upper frame. If the C Channel (that defines frame perimeter) is oriented so the open part of the C is facing the interior of the robot, the exterior surface makes a good surface to attach the gusset plates on both upper and lower frame.

2.C Channel Orientation - If gusset plate is not allowed on exterior of frame, would a C Channel oriented with the open section facing the exterior of the robot (bumper would be mounted to this) be legal?