How can I turn off vibration without going into silent mode on a rooted Nexus 5 with stock firmware?

I see a related question but I do not see an applicable answer to my exact situation. I want to turn off vibration on notifications, without diabling notification sound along (so notifications should still play sound, just not vibrate). I'd like to do it using Tasker. @Izzy recommended the "Vibrate On Notify" toggle but that doesn't seem to be available for me; unsure as to why (see image below). I'd be open to installing Xposed Frameworks module if needed. Any ideas? *Tasker* window (click image for larger variant)