I decided to compare the results of a simulation using a Slip wall planar face as a pseudo ‘Symmetry Plane replacement’…
And the results of your suggested Custom>SymmetryCondition for u,p k,w (note this was incompressible CFD)
The good news is that they both converged almost identically and to virtually the same results…
So, unless I need to selectively un-select u,p,k or w on the Custion>SymmetryCondition tab, I will continue to use the simpler ‘Slip wall planar face’ to achieve proper symmetry for my results…
EDIT: I can also say that using a Symmetry Plane BC also provides virtually identical results as the above two methods and here is a link to that sim run…