Can I change from a Non-B visa and work permit to a Non-O visa for guardianship without leaving Thailand?

The user is transitioning from a Non-B visa with a work permit to a Non-O visa as a guardian on their child's ED visa. They are specifically asking if they must leave Thailand to change their visa status and whether the required 500,000 THB needs to be in their bank account for one month or three months before applying. Two comments provide answers: one states that it is possible to change the reason for an Extension of Stay to support a foreign child without leaving Thailand, and the requirement is 500,000 THB seasoned in the bank for 30 days for the initial application. The other comment warns that one generally cannot switch from one Non-Immigrant visa to another without leaving Thailand but indicates that changing the reason for an Extension of Stay is allowed.