2nd skin is generally preferrable, but some stockings are too elaborate for this to work.

Also, if you need to drastically morph a figure, a 2nd skin stocking will distort. An actual stocking mesh can be "bespoke UV mapped" to fit the final morph.

Here's an early WIP for a V4 character I'm working on:

The skin texture still works quite well, but' I'm pretty sure all clothing needs to be heavily modified or custom made to look good on her.