My ds is very similar to mysonben he has sli, and mild asd (asd traits, waiting for ados test)... he was at ms nursery attached to our local primary, he has just turned 5 and is now at school, P1, Scotland.
DS had 1 to 1, who sort of shadowed him, to encourage him to play but would try and let him get on with it, the thing is he found it much easier to communicate with an adult, they understood to make exceptions etc... ds did form a bond with a another boy who has an asd
"The first year there, he never played with the other kids, he has only started paralell play and limited interaction (mainly imitating).
He does a lot better in small groups, when the nursery isn't too busy.
He gets two 30 mins a week with 2 other kids of social games, language development activities" - my ds sees early years support teacher(same person in P1, which is good) for this, but really had very little interaction with other children, his choice - he wasn't mature enough to be any other way, imho.
"He has an IEP for the staff to focus on his problems mainly speech, eye cotact, turn taking and sharing.
He has a visual timetable" also the same for my ds.
DS was in pull up pants until he turned 4, he slowly got the hang of going to the loo, was very reluctant to go at all, so no accidents.
He started watching mr.maker online and then became very slowly more able to try craft, painting and some drawing, but this took until his last term really, the staff encouraged him but that is all they could do - I think his imagination wasn't there, so with hindsight I understand why he was reluctant. DS is still much happier at home, where we understand him easily, nursery was hard work, lots of noise, change etc - even though he improved massively over the 2 yrs. After every holiday they noticed how much he had improved.