It sounds like you are doing everything you can. The fact that you are
remaining flexible is a good sign--you know you are dealing with a moving
target.
Tiredness is a primary trigger for our son's larger outbursts as well.
We're starting to wonder if he may have a sleeping disorder, because we're
just not sure if he has slept well on some days.
He has been a bit more of a terror lately, but what we're seeing is more
akin to typical toddler behavior--taking toys, pulling hair, getting into
things. It's just so much magnified since he is already bigger than his
older sister and almost as big as our Kindergartener. In fact, those two may
be wearing the same size clothes pretty soon, and that means our
hand-me-down plans come to an end until Gideon is a size or two ahead of our
other son.
We have another child who has/had sensory integration disorder. He was
hyper-sensitive to touch and some noises. It can be different for each
child. Most younger kids can only handle so much sensory stimulation before
they go into overload mode, and they most often act out when they get home
(it's where they feel safe pushing the boundaries). As far as nomenclature
goes, we'd still call them tantrums--we just understand that there is an
underlying reason for them, and we try to figure out what those reasons are.
We try to keep a routine, but we're not as formal as some (it's hard to do
in a family our size, with as many kids going in as many directions as they
are). We can tell that Gideon doesn't like to deviate much from that
routine.