Can disabling IE Protected mode improve performance on RDS server

Hi there,
We have about 15 - 20 users on an RDS server and different users often experience several seconds lag when entering text with their keyboards.

We've found CPU usage at different times averaging 30-70%. We have doubled the RAM and added a second processor with the RDS set to use it as exclusive numa node, but the problem doesn't appear to have ceased at all.

Looking into the threads of highest CPU time user processes (often IE11) with process explorer, we found reference to protected mode and this being about 80% of that process demand.

I'd like to test if there are performance improvements with all users having Protected Mode disabled via GPP.

This setting however isn't avail in GPP and we have Win 2008 R2 so IE8 is latest version listed. I've manually edited an IE8 InternetSettings.xml like so http://support.microsoft.com/kb/2733083
add disabled="1" to every XML tag that includes the following value:
name=”2500”
Also set version tag max="11.5.0.0"

But...