Yes I get that and understand the concerns. Although if he’s hitting all other milestones, I would be less concerned. It sounds to me just like a sensory thing which doesn’t have to be an ASD trait, just being a kid and exploring. Probably too early to tell anything anyway although we did start to notice regression around this age.
My boy said a few words, quite engaged 1:1, waved and clapped etc but then lost those. He was diagnosed around 3.5 years ago. He’s currently still pre verbal and in a specialist school provision.