I completed the wiki page about worldmap encounters:
http://wiki.ffrtt.ru/index.php?title=FF8/WorldMap_wmsetxxTo summary my changes, I identified rates sections and "after Lunar Cry" special encounters.
Encounters after Lunar Cry (Sections 5 & 6) seems not linked to Section 1 or another section, I guess this is hardcoded somewhere.
By the way I found occurrences of UFO, PuPu and scripted Thrustaevis battle in section 37, I think this section contains scripts. And its format looks like sections 8, 10 and 12.
I haven't found Pampa Sr battle.