You would have to amend the GDL code.
Instead of 1/16", you can enter .0001" if you want, it will read as 0, yet shouldn't affect dimensions it's so small.
You could also ask your reseller for the Modular Joinery Object. Do a search here if you want to find out more.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"