This is one of the situations...
Here is just a simplified style out of the bigger picture, so don`t ask me why
The Linear0 is in tile mode (possible count) and it is split to the sections by the NULL segment and the numeric Evenly Distance node.
I set the X size for the BOX Segment by Arithmetic Node (In the final, nested Generator will go instead of the Box Segment)
Second Linear1 generator will use Nested TEAPOT just for Start/End position.
The size of Start/End segments is used to Limit the paddings of the first Linear0.
Change Evenly Distance and X Size parameters - So far so good.At some point, I need to Fit X Size of the TEAPOT to the SectionLenght of the Linear0.
When Arithmetic node is connected to the X Size returns 0.
When Transform X Size is connected returns value 100 which is the original BOX size even tough the Transform2 operator override it with Arithmetic XSectionLength.
Please check this if all those issues are just a bug or the code needs to be updated since all the connected generators Attributes are correctly displayed in the Arithmetic rollout.