If any body has been using the nearly excellent QuickJoint extension for adding tabs, gaps and slots you might want to have a look at this.
Githib QuickJointis great, except it only adds kerf to slots, not to tabs and gaps.
I have a really kludgy fix for this that adds kerf to the gaps (where the tabs will go into). You have to user select when you want it on and it only works on vertical and horizontal lines - anything else and it will go horribly wrong.
If you’re interested, drop me a DM and I’ll send you the files.