We've seen this one before ! Looking at GSV, there have been a few minor signage changes, but where you got the idea of it needing red tarmac, I don't know ! There's nothing like that in the regulations.
If you do a search of the London Tribunals statutory register on Mitchell Way from 1st Jan 2021, there have been 21 adjudications, most of them unsuccessful. There was an issue with camera approvals until quite recently but I think that has now been dealt with. I'm afraid the likelihood of a successful appeal is low, in my opinion.