I see several TMA and I are thinking along the same lines
🙂
You can also use any door, panel choice set to 'Empty',
minimize and/or turn off casing and frame,
turn threshold on extended both sides but set its dimensions to not go past the wall and again all dimensions to 0 or fake it with .001"
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"