Assume that husband was granted ILR using SET(O) as a PBS Migrant and
not granted ILR using SET(LR) under
Long Residence:
If you are
extending as a PBS dependant, then the maintenance required is
as if husband was still a PBS Migrant.
Under the
Immigration Rules and
Guidance, there is no requirement to make an early
premature extension. However, you should be aware that
some caseworkers have difficulties in understanding this.
But as you should qualify for ILR within 3 years anyway, you may as well extend now, to prevent hassle with an irrational curtailment team. Or, if not travelling, when extending, you may wait until a getting curtailment notice or until shortly before your leave expires.