Overlay options for action hacks

[roberte]

For many of the action hacks such as the decorgal hacks, Aikeaa animation paintings, etc I understand there are overlay options that allow one to do 2 or more activities at the same time. I know that some of them have this option built in, but none seem  to give a clear understanding of exactly how it is accomplished.

Also, I wonder if it possible to combine overlay activities from different hacks to create a combined action or if it is only possible within the structure of a single hack?

Can anyone provide suggestions how/where to find info?

Thank you.

[Gwill]

Ask whoever made the hack.