I've made a small patch to set the number of pages full refresh menu vs reading ( when clicking on bottom or top menu to have some full page refresh after 6 pages, but if when reading to be 1).
Attached , files needs to be copied over last koreader-cgm.zip (in this thread).
the extra option is set in defaults.lua like this:
-- number of page turns between full screen refresh
-- default to full refresh on every page turn
DRCOUNTMAX = 1
-- DRCOUNTMAX_inopt will be used when some menu is activated
DRCOUNTMAX_inopt = 6
(the file from zip ./koreader-cgm2-extra/add-to-defaults.lua is NOT used, just a hint that this new opt goes into defaults.lua)