FLR(M) from inside UK - Super Priority not available?

Applying for a spouse visa (FLR(M)) for the first time - just got to the end of the visa application form and I'm not getting an option for super-priority?

Does the option only become available when a slot is available? eg I need to try again at 1am/similar

I've seen that priority and super-priority are limited to visit visas for people outside the UK but we're applying from inside the UK.

And based on the info on the website (https://www.gov.uk/faster-decision-visa ... ide-the-uk) I was expecting to be offered a next day appointment.

Alternatively is there some combination of answers which forces it down the standard route and doesn't offer priority?

It is available and if you don't get it then try again later at 1AM as it is first come first serve.

Also note that super priority has nothing to do with the biometric appointment. Super priority is a ukvi service. The appointment is with UKCVAS who is a third party agent for enrolling Biometrics and identity check only