Attending two graduate schools and CPT

USA F1, F2 Visas - CPT - OPT
1

If one studies in graduate school A in US, can he use more than 12 months full time CPT? I heard that more than 12 months full time CPT will not allow him to apply for OPT.

If he later studies in another graduate school B, will his usage of full time CPT in school A affect

  • whether he can apply for full time CPT in school B, and

  • the maximum time his full time CPT will be allowed, and

  • whether he will be able to apply OPT?

Thanks!