> "Do I add or multiply identical effects that multiply values?"

[Sage Advice has this:][1]

Mike Mearls says "Identical effects do not stack."

Jeremy Crawford says identical non-spell effects *could* stack.

As far as I know this has not been resolved any further.


  [1]: https://www.sageadvice.eu/2015/08/18/does-paladins-aura-of-protection-stack/