hi thanks for your info there is only one adjustment screw and that only does the tickover there are openings for the other adjustment you mention but there are no screw visible to adjust
On you carb the adjustment that is closet to the intake is the low the one closet to the air filter would be where the Hi would be. If there is a adjustment there for the L I would still turn it out ccw by half a turn and see if the saw runs any better.