Disability tax credit - use on child's return but still list as dependent?

My son has a signed DTC that I normally add to my return.  However, 2022 he made enough income that it may be a benefit for him to use his own DTC on his own return.  How can I apply his DTC to his own return and still keep the dependent amount and MB Caregiver amount on my return?  Am I just hooped and have to claim everything on my own return?