I am travelling from a country that requires a visa. I got the six month visa last year, but I couldn't travel due to well-known worldwide difficulties. In the meantime, I got a visa for Schengen Area (Germany) and am currently in Germany. Can I just make a try to enter the UK with the purpose of tourism and be granted an exception/concession to enter for two or three days and there's not a zero chance of me being allowed in?
Reasonably the answer would be "no", but I got several similar concessions some years ago on stopover flights through the UK when my connecting flight was due next day, when I missed a flight entirely or when my connecting flight was due in several hours, but I was feeling unwell. There weren't any issues and in every case I was granted a stay for a day or two (I can't remember the exact time range that was given).