Hi Steve,
That's an interesting question! Not least because getting an appointment at Alicante foreigners' office is extremely difficult at the moment.
In your position, I'd be thinking of making preliminary enquiries with a gestor in Spain, to check what tolerances the Spanish system may allow in the event that you can't get an appointment within your first month. Personally, I would expect that, so long as your application has been submitted online in Spain, you will have met the "apply within 1 month of arriving" requirement, even though you won't have had your fingerprint appointment - but it probably makes sense to have that confirmed. I know a gestor who deals with Alicante foreigners' office, so I'll ask him and get back to you.
Kind regards,
Kim