How about going into the garage where taxi drivers go in great suffolk street? use your charm and make some excuse as to why you have to leave your car there for only ten minutes or so..i.e. get your 101 year old granny a birthday card! Or just explain to the girls in the shop the truth?
The red route bays would be on SBR itself or Blackfriars Road, but you need to check any red route bays for cameras as TFL are very strict on the definition of unloading (apparently, unloading yourself to go to a shop doesn't count!).
Large vans illegally park all the time on the section of union street between SBR and Borough High Street, on the yellow lines and even on the wide pavement bike lane. The council occasionally sends cameras up there, but generally the vehicles appear to get away with it, despite causing a right blockage in the road. Which bit of SBR are you going to?