Just for clarification, the bubbly paint was present on my £11500 2014 bike at the time of purchase but not easily visible, I certainly didn’t see it. As mentioned, when I then washed it a couple of weeks later the flaky paint lifted off leaving bare metal visible the size of my finger nail. From the outset the dealer was helpful, they agreed that as an approved used bike it should have been spotted by one of their technicians and certainly not offered for sale in its present condition. Fast forward a few days, new engine authorised by BMW and fitted. It cost them over £8k from an £11500 sale to put the matter right.
Whether others think this is an over reaction by the dealer or whether others think my expectations were too high, Consumer Law is there to protect the Consumer. The dealership would not have taken the steps they did had they not had to.
If the paint application on the frame and engines were done to a higher standard, possibly there wouldn’t be a need for so many Warranty claims.
Anyway, I shared my opinion and experience to provide options for the OP, the rest is up to them.