I’m not sure if it has come up before, but for some montages where masked Adjustment Layers need to be transformed with certain Layers (S.O.) but multiple of those elements share adjustments it might be beneficial to have »Smart Adjustment Layers«, where changes to one of them get copied to others automatically.
It's a pretty nice idea. Maybe add the possibility to lock two, or more, adjustment-layers together.
Perhaps another benefit of having Smart Adjustment filters would be the option of applying more than one blend mode to them.
We often have the need for this. For example, it would be great to be able to apply the Multiply mode and while maintaining the effect, also apply luminosity to remove any colour shifting. Adding Smart Adjustment layers to PS is a great idea.