during transition period also cannot?

for example if i want to terminate unifi and sign up celcom, cannot have celcom connected before i terminated unifi? like that will have downtime rite?

worst case if one's area has fibre ports full, during the transition if terminate unifi first, the port maybe taken by others rite?

I see. Thanks.

For DiGi, needs to go to DiGi store to do rite?

Same for celcom?