I don't have any experience with kgpanels but you could hook LoggingCombat. One possbile way (dry-coded) would look like this:
Code:
OnLoad:
local function frameToggle(input)
if input then
self:Show()
elseif input == false then
self:Hide()
end
end
frameToggle(LoggingCombat())
hooksecurefunc("LoggingCombat", frameToggle)
This assumes kgpanels runs OnLoad only once after frame creation like if it were to be specified in XML. Otherwise you would need to build any kind of check if you already hooked LoggingCombat as to not hook it over and over again.