PSC appointment Help!

Hello everyone, I am trying to secure a PSC slot for my wife SET(M) application but almost all PSCs are showing no availability for next 45 days! As I live in South I'd prefer Solihull or Cardiff. I have been to Solihull before so I know where to go and where to park etc. so that would be first priority and then Cardiff. Problem is I am only getting appointments for Sheffield and that too in July. She still have time as her visa will expire 23/08 so my question is what if I go ahead and book a slot in Sheffield now, would I be able to change my date/PSC if I get a favorable appointment in Solihull or Cardiff? I know back in days when it use to be PEO you could change PEO/date etc. but here I am booking appt as part of online application so this is a bit grey area for me that if I book an appt Sheffield would I be able to go back and change it? Any help would be much appreciated!

Reschedule appointment is not always possible so you might have to cancel the appointment and book again , fees refund takes few weeks to be processed..... as I tried to reschedule appointment but failed to do so I had to cancel it ....

If you’ve got until 23 Aug that’s plenty of time to get a PSC appointment in the South. The booking system is dire but appointments are released from time to time, last Thursday a large batch was released across the country

Thank you guys I will keep trying for next few weeks.

Just as a follow up are/were available appointments at every PSC one hour ago for July 7th