Does ttlmax apply to user caching?

So I'm trying to figure out what is going on with my user caching. After keeping an eye on the user cache entries, it seems something is clearing everything out. At first I thought it was the ttlmax setting, but changing it to 0 does not keep entries after a certain amount of inactivity. I suspect it has to do with the Application Pool that PHP is running under. So I guess I really have a few questions;

1. Does ttlmax apply to user caching? If not;
   1. Is there a WinCache timeout at all which applies to user caching that would clear entries out?
   2. Or are entries kept until the user cache is cleared or the application pool is recycled?
2. Anyone aware of a any other timeout that would clear entries?
3. Does the Application Pool have a timeout that would clear WinCache?

EDIT: Another clue, the Cache Uptime continues to be reset after so long of inactivity (for all areas) which again points towards the AppPool...

Thanks for any feedback!