Moving family to Taiwan and Applying for Household Registration

As for conscription

Article 3 of Conscription Regulations for Naturalized Aliens & Returning Overseas Chinese says

A draftee-to-be in the status of an Overseas Chinese having not established household registration in the Republic of China previously shall be subject to conscription enlistment according to law upon expiry of one-year period beginning the day next to his initial household registration following his return to the Republic of China.