Toddler Tantrums, Sleeping, and Sensory Processing

What possesses a child to throw himself down screaming because his mother offered him a snack when he didn't want one? What a TEMPER.
Admittedly, I had just tried to put Kittyboy down for a nap (which I thought he needed, because his temper was a bit over the top), and that hadn't gone well, and it had ended in him screaming nonstop while pounding on his door. THAT means the napping attempt is over. And after that, it had taken 5-10 minutes of holding him very tightly compressed on my lap, folded up sort of, saying, "Calm down. Calm down. Calm down. Calm down. Calm down. Calm down," while the shrieking subsided to sobbing, and then he started trying to catch his breath between sobs, and then there were about equal amounts of sobbing and gasping, and so on. After he seemed pretty much done, I offered him a snack. He then collapsed to the floor and cried nonstop for another ten minutes or so, then on and off for another ten. I thought he was going to cry himself to sleep on the floor, in which case I'd have let him stay there. He didn't. He eventually decided that his tantrum wasn't worth the bother, since it wasn't getting a reaction. But almost half an hour's worth?
And we're supposed to keep in mind that "children with sensory processing issues can be more easily distressed," more violent WHEN distressed, blah blah blah. Holding him all folded up tightly does calm him down, the deep sensory input. But that doesn't mean the tantrum started from something actually bothering him, so much as just His Will Being Contradicted. I do think the sensory issues may make it more difficult for him to calm down after working himself up, but he does also have a Temper to end all Tempers. I wish there were some way to separate the two - to know when it's a tantrum to be ignored versus when he's worked up enough that he needs outside help to get it together again. I think I'll just keep drawing the line at "Is he stopping to breathe or not?"
And then there are still the unhappy wakeups. I may have found ways to mitigate those, OR I may just be grasping at whatever illogical, inconsequential little thing I find, in the manner of throwing virgins down the volcano and thinking that's what keeps the Fire God from obliterating the island. Continuous shhhhing, rubbing back, while not speaking or touching him or covers in any other way - good. Appears to soothe and calm after a few minutes time. Speaking to him, moving him, making eye contact, or rearranging covers in any way - bad. Speaking to him WHILE making eye contact, taking his covers off and sitting him up all at the same time - disaster. I believe this to by why he used to be SO upset sometimes and whatever I did seemed to make it worse, because of course what I would do is pull off his blankets, pick him up, talk to him, etc, exactly how you are supposed to console a baby. Then I noticed one time that eye contact seemed to distress him more, and then another time that taking his blanket off intensified the crying. So now I've got this list, should he ever take a nap while being babysat and wake up crying - say nothing apart from shushing, and that as rhythmically and soothingly as possible, rub back the same way, don't touch him otherwise even if he's laying awkwardly, don't move blankets, and if he's facing you, don't LOOK at him. And basically, wait for him to stop crying. start moving around, and get up from the bed on his own timetable. There is a sort of logic, taking into account that trouble with sensory processing can make waking up distressing, that perhaps limiting any change or input other than that which is necessary to let him know he is safe really is the way to go. But it's so counter-intuitive!
So the temper and tantrums are worse - the waking up is starting to go more smoothly - I don't know that that's a satisfactory trade-off, but such is the state of things.