How to make a feature/part completely invisible in Revit Family File?

The visibility setting is not enough, I would like to completely have the feature/part disappear without having to use preview mode everytime.

That's a tough one, I'm not a Family expert, but what if you were to assign a material to it, make it transparent (there but not visible?)
Or assign some other property to it where you can filter it out (using view filters)

Just some thoughts

make the element you want to hide a nested family and then apply a parameter to the visibility of the modeled elements (extrusion, sweep, etc.) within the nested family and link that parameter to the host family. See pic for result. One extrusion is in the host family and the other is in the nested family.