PLEASE HELP: Advice from UKVI on switching from fiance visa to FLR (M)

[Apple_snaps87]

Briefly: I'm an American engaged to a British citizen. We intend to live in the UK after we get married. I applied for the 6-month marriage/CP visa, i.e. the "fiance visa," from outside the UK. It was approved without issue, I entered the UK and we recently gave notice to get married next month. Everything's on track and we continue to meet the financial requirements and have money set aside for my NHS surcharge and the next application fee.

I had a question for UKVI (not including as the question itself isn't relevant to this post) and as part of the answer, got this back, copied verbatim from the email I got from UKVI:

Also be advised that the 6 months marriage visa can not be extend or exchange to any other category of visa. If you decide to settle in UK after your wedding, you will have to leave the UK and apply for a settlement application from your home country.

Is this advice accurate? My understanding was that while the initial "fiance visa" had to be applied for from outside the UK (which we did), switching over to FLR (M) could be done from within the UK once we were married. Do I have it wrong? If so I'd like to know sooner rather than later so I can make arrangements, but I've seen several anecdotes about people going to in-person interviews for their application in the UK, so ... mostly right now I'm panicked and also confused. Help?

[CR001]

How much did your 6 month visa cost??

There are two different category marriage visas. One costs around £85 and the other £1523.

[Apple_snaps87]

How much did your 6 month visa cost??

There are two different category marriage visas. One costs around £85 and the other £1523.

The latter, more expensive one. I know what you're getting at. It wasn't the quickie visit visa!

[CR001]

Then it is fine to switch to FLR M if you have the more expensive visa.

[Apple_snaps87]

Then it is fine to switch to FLR M if you have the more expensive visa.

Thanks, that's what I thought. Just wanted to make sure I wasn't going insane (I even dug up my payment receipt to verify it). I'd heard that UKVI advice could be somewhat bonkers but that's next level. Appreciate the quick response.