I'm wondering if you asked your prescribing health care provider about this. I think since the sores are scabbing over, it is probably alright, but my concern would be infection.
If the makeup is old or could be contaminated, or if you use a brush or other reusable applicator on the sores and put it back in the container it might not be a good idea. I did a search for information on this but couldn't find anything specific.
I definitely wouldn't put anything on any cracked or open skin, as that is a pathway to infection and shingles is bad enough without having any of the sores infected. Again, I suggest asking the provider you saw just to be sure.
We have a page on shingles if you would like to read more: https://www.empowher.com/condition/shingles.
Good luck and thank you for writing.