How to get Powershell-ISE to release Cmdlet DLL -

I am developing a CMDlet and using PowerHale-ISE to test. ISE is locking my DLL and stopping it from rebuilding and then reloading.

I have tried to call PS-snapin to remove, but DLL remains closed. As the roman says, it can not be AFAICT, it's not a PowerShell ISE problem as much as

It's an assembly with loading. NET is the issue. NET does not support assembly unloading. It would be nice if there was a way to add snapin through a secondary appendaman and then unloading the entire app docs is not aware of any attempt to do this in the host.