I think de-seaming the rear is alright, but a smooth boot lid doesnt cut it for me.
I have smoothed the rear on mine but as above, I'm not a fan of the smooth boot lid. I always think the way you have to mount the number plate elswhere spoils the overall effect.
At least the boot lid is easy to swap if you change your mind.
But hey, it's a mini and whilst differing opinions are good, if it works for you............................
Good luck with whatever you decide
Regards
Steve
Where is that forlight from?