I'm trying to mimic this, where a taxiway's width suddenly changes:
When I create one segment and give it a width of 30 m and create another segment and give it a width of 20 m, both taxiways appear to have the same width. (They're obviously both the same material in real life, but I changed the left one to brick to illustrate that the SDK is aware that these are two different paths.)
Am I missing something? Just for kicks, I made the left one 10 m and still no change.
Left taxi path (the one in brick):
Right taxi path: