That's probably all pretty good advice, but it's not universal. I don't have a 590S but there are many reports of it being "undermodulated" when adjusted per the instructions. Possibly the ALC indicator is simply inaccurate and reports lots of ALC activity when there's actually very little. I really don't know.
Originally Posted by WA9SVD
A government which robs Peter to pay Paul can always depend on the support of Paul.
-- George Bernard Shaw