Grandson with ASD

ive had my grandson living with me  since birth he’s 4 now. He attended nursery from 4 months old when he got to 18 months that’s when the behaviours started initially it was biting the other children which firstly was put down to bad behaviour however it continued as he got older he also started to bite tables cupboards anything really. He still bites now and headbuts I find when he gets over excited these behaviours tend to come out.  Soeech  was also delayed he also became quite violent both at home and nursery this has got worse over the years he has regular meltdowns both at nursery and home the staff have had training around  his needs through the inclusion team we also have early help in place. My grandson also has Input from speech and language and the pedictician. Going out with him good days and bad days he also takes his shoes socks off and clothes if gets chance in public when having a meltdown which can be quite embrassing  . I would say they have more behaviours at nursery then I do at home I worry how he will be when he starts school next year. I’ve been told he will have a good transition which will take longer then the other children . He does not like change at all he has a strict rountine   he has to stick to. He is  very sensory had to have labels to hold hates showers  and hand dryers in the toilets.  He’s good in other ways fully potty trained last 5 months which was my worry thought never would happen . We have bought him a kitten this has really helped him they are the best of pals 

I guess my question is how was other people’s childrens transitions to main stream school ?