Defrag Tools #133 - App Paths

In this episode of Defrag Tools, Andrew Richards and Chad Beeder look in to Microsoft Symbol Proxy (SymProxy). SymProxy is used to cache symbols (positive and negative) from one or more upstream symbols servers. We cover the installation into IIS, and the monitoring via Performance Monitor and Event Viewer.
Timeline:
[00:00] - Overview of Symbol Proxy (SymProxy)
[02:00] - SymProxy (MSDN)
[04:25] - Enabling the IIS Features required
[07:37] - Site level MIME Types: .* | application/octet-stream
[08:58] - Symbol "Theory" (MSDN)
[10:40] - Installing SymProxy with Install.cmd and staticContentClear.xml
[14:00] - IIS Manager - view the site
[07:22] - Registry - HKLM\SOFTWARE\Microsoft\Symbol Server Proxy
[23:50] - IIS Manager - Change Application Pool to always run
[26:45] - New Symbol Path - SRV*c:\my\sym*http://localhost/symbols
[27:26] - Performance Monitor - Symbol Proxy\<_Total>\*
[32:21] - Event Viewer - Applications and Services Logs\Microsoft\Windows\SymProxy
[34:14] - Performance Monitor - Large Server example
[41:47] - Helps reduce your processing overhead
[43:45] - Email us your issues at defragtools@microsoft.com
Any reason to not have a much longer missed cache ttl? If the third party symbol isn't there, it will never be there. Why bother going back? I'm trying to imagine why I wouldn't want to roll my own instance with a max ttl.
K-sh?
Is that anything like cash (cache)?