Correct me if I’m wrong but aren’t backmarkers meant to move off the racing line for the leaders?
Its an unwritten rule in F1 that they do . . . . at club level from day one you are told to hold your line, do not deviate or do anything eratic ( like Bottas did yesterday with his little blip ) It is the responibility of the faster car/driver to pass safely. The blue flags are to advise a faster car is approaching.
In reality a slower car/driver will often move aside if on a straight with space to do so. You can't just dissapear though, and you certainly don't weave or dart about like F1 drivers do.