@Michelle this is definitely something to think about, I’ll be due to return to work in May/June and would like to find somewhere that he will be comfortable for longer days.
It sounds like he doesn't know how to communicate his frustrations to them properly or they don't know how to best handle him. My LO is same age, with potential adhd. She really struggles to control her emotions and does pretty much what you explained above but she is like that at home and school. I'd either look at a different school, maybe one that is known for being able to deal with special needs. Not saying he has it, but they do treat kids very differently and maybe they can teach him how to better control his emotions.
Sounds very similar to my son.. since the summer he's been throwing toys sometimes or will push someone with no reason apparently.. they've said he seems to lack impulse control but that's normal for this age. He has excellent speech but I think struggled communicating his feelings. It's so frustrating because he's such a good boy but obviously something sometimes triggers him. Our babies are still little so just got to keep praising good behaviour and maybe adding consequences to the not so good.. it's tough!
Sounds like he would be more suited to a childminder - suggest exploring that option. It’s cheaper and more flexible too