WMS problems revisited

A number of geocortex users in Australia consume the same WMS which has 90+ layers in it.  It is causes us no end of trouble in geocortex. 

For example, our site.xml goes from 1500 lines to 6500 lines with the addition of the one WMS in 3.7.

How does geocortex actually obtain the layer name? 

Could we manually remove layers from the site.xml?  

At this stage if I add this 90+ layer WMS into geocortex 3.7, and while it nearly kills the rest manager, it's not including the layers names in the wms requests. 

It does for the 8 layers WMS sitting right next to it in the same site.

Is there anything we can do to speed up such massive WMSes?