Motorcycles in Cat N can indeed be written off more than once, but this depends on the circumstances surrounding each incident.
However, the history of previous write-offs will remain on the vehicle's record, which can affect its resale value and insurability.
If considering purchasing a motorcycle that has been written off before, it's essential to check its history. Any motorcycle with multiple write-offs may have underlying issues that could affect safety and performance.
My Last bike, also a Kawasaki, a GTR1400 was a write off, Cat D at the time in 2017, I knew this before privately buying it as a project bike. No issues with insurance companies.
I fully inspected it, stripping back off all the plastics to check possible hidden damages, non were found, some panels I replaced rather than repaired, basically rebuilding back to a safe ride-able touring machine with only few battle scars.