For about half of the UK circuits it'll be fine with the bungs in, but it'll fail Bedford on the drive-by and that's one circuit that's close to me that I have always enjoyed driving in the past and want to go back there. 'Tis a shame, but that's the sacrifice I need to make unfortunately.
I've thought about getting another exhaust, but then I'll always be chasing the sound that the K1 made and the louder I go the less places I can drive, so I'll just concede defeat on this one.