Set it on the web server side? Litespeed is the web server. Our load balancer uses a header other than X-Forwarded-For making the Client IP Header feature useless. We can't change that. Mind you, we don't use LSLB.
Aside from this one example of different client IP headers, being able to specify a logFormat that is shared by all VH would be supremely beneficial. The method you keep linking me to will not accomplish the need presented.