Can you use the same passticket to signon to multiple regions within the same CPU/LPAR?
Yes. SIGMULTI must be specifed for the passticket definition in CA Top Secret.
TSS ADD(NDT) PSTKAPPL(application_name) SIGNMULTI
SIGNMULTI allows the passticket to be used to signon more than once during its lifespan. Without it, passticket will only be allowed to sign on once and all subsequent passticket signon attempts will fail.