Sorry I don't know the answers. Someone on here may or there may be other posts about it in the group topics. As long as you have the documents and prepare then it doesn't take very long and there are lots of agencies that will help but at a cost.
Are you sure you can't apply for a 60 day tourist visa from Spain.? The 60 day tourist visa is now an evisa you don't have to take your passport to the embassy. You just upload your docs and info on line then they email you the 60 day visa. Print it out and hand it to immigration and they stamp your passport. As its now an evisa you may be able to do it from Spain using your UK passport. I went on a 60 day evisa and extended 30 days in Thailand without any problems but admittedly I was in the UK when I applied on line. Why not try it anyway from where you are?
all should go smoothly if you submitted all the documents needed but beware a lot of people are receiving scam emails saying there has been a problem with your documents. If you get an email like that do not click any link or enter any personal info asked for without checking back on here. Or go through the posts on here so you can see what to look out for. If in doubt check back here a lot of folks here are very knowledgeable.
for pointing out my mistake. If not vaccinated the rules are different. I apologise for my error. You can check the curent requirements in UK on this link to the UK Govt website
Oh yes you are of course right Mike I was fully vaccinated. If not its a different matter. And I had to show my NHS Covid Pass (Vaccination Certificate) printed on paper at check in as well as the PLF.