Purpose of "Support compute skincache" option

Does anyone know what use it has and what it does? Originally I thought that I would need it, whenever I have characters with morph targets (for correct light/shadow calculations), but after having done some experiments I’m not so sure anymore, because it doesn’t seem to be necessary for that. Can someone enlighten me about the use of this option in the project settings?

I made some new tests and indeed it is necessary if you work with morph targets, otherwise the shadowing will be incorrect.
My UE4 settings for models, which have also shape keys and normal maps are as follows:

Is this the way to go? Do you have similar settings?

But when using the machine a model, it will cause some problems. The chamfering is not so correct at the edge