Personally I wouldn't do it. You have 2 bikes which are totally different riding styles which provides you with options. You could convert the R6 to a dedicated track bike and avoid the hassle of changing it back to street when you want to just take a lazy ride. Or even just weekend twisty duty with it and using the cruiser for daily commute / cruising.
So long as both bikes are mechanically sound and haven't turned into money pits, you've got more value in what you have in my opinion.
So long as both bikes are mechanically sound and haven't turned into money pits, you've got more value in what you have in my opinion.