Hi @LLuk
Blocked (white) values will inhibit move on dark from operating on any fixture that is blocked in that cue. MOD can operate on the following cue if the fixture isn't blocked assuming that fixture is not used until later.
COPYing cues will result in blocked values. Updating or recording with SmartTag off may result in blocked fixtures if you tagged that fixture but actually didn't change the intensity.
Using UPDATE with SmartTag enabled will clear the blocking and track if possible.
If you've seen other behaviour (and your opening text suggests you do), then Edward will probably need a little more info on your exact programming sequence, a showfile and which ZOS version you're using.
Reading your paragraphs your understanding in each seems correct to me.