Our DS9 (DYS) was assessed at age 3 and 6 because of struggles arising out of his intensity. Two different assessors. Teachers were concerned about potential ASD. Both assessors found him to be profoundly gifted but not ASD. For all his life he has had super intense interests like you describe. They have ebbed and flowed over time (Supercuts, ocean life, rocks and minerals, magic the gathering, Hamilton and the revolutionary war, politics and the presidential election come to mind). I can't say whether this is relevant to you. And I'm guessing that a lot of the coping strategies are the same either way. But DS is apparently not on the spectrum despite sounding similar to your child.