Anyone know of any 4.x feature or module that allows assignment of skin / container by portal alias?

ie.  portal id = 1 with 20 aliases. 

need to assign different skins to each alias.

Portal ID is the same for all of the portal aliases.

Lets say we have 15 domains listed as portal aliases for portal id = 7.  I would like to assign different skins to each of the portal aliases.  Content will be the same just the look and feel will be different.

Currently, according to my knowledge, the DNN only supports the skining at the portal level not at the portal alias level.

Your idea is excellent. In the skins table if we create a relationship with PortalAlias table by creating a column in the PortalAlias table. then we can define the skinning at the alias level. you also need to modify the page that check the portal skin. I think you can extend the functionality of the portal controls.

This extesion will provide the ability to attach the skin with the portal alias.

There will be some consideration also that can occur during the development.

Hope you will try this and make the community happy by providing the upgrade module of the portal.