Applying for a visa to sit an exam in the UK. But I probably won't make it in time. Should I still apply?

So I am applying to go to the UK to sit an exam on the 26th of November. The exam is listed as one of the legitimate reasons to go to the UK.

However, given that the visa takes around 3 weeks and I travelling from a country that is not on the "List" so I will have to quarantine for 2 weeks, I probably won't make it unless I get the visa by the 11th of November. After speaking to a few people this seems unlikely. But I did travel to the UK 8 years ago so I hoping this may speed up the application process.

Now the question is: Will my application get rejected on the spot due to the reason that if the visa is given to me a single day after the 11th I would not make the exam due to the 2 week quarantine? Do they consider this when giving out visas?

I added a comment to my application stating that if this exam gets cancelled due to COVID as it has happened before or I don't make it, I would like to have a visa ready so I can jump onto a plane and go to the UK as soon as another seat for the exam is available. Will this help my application?

It sounds like you are applying for a Standard Visitor visa, not a temporary work visa. If so, you have posted in the wrong topic.