I think BT is good only if you have a reliable secondary car and this isn't your primary. I imagine you need quite some more internal work done and the car break down chances are higher, thus you might be carless for some time.
K04 is great for keeping the car reliable and making decent power.
I remember reading comments on YT from non-VW car enthusiasts and they didn't understand why we would throw an OEM part on our cars to make them faster when they compared it to just getting Golf R numbers rather than going bigger.
Little do they understand, we aren't making stock Golf R numbers since we are installing it directly with a tune. We are also putting all the power directly to two wheels as opposed to 4 (not that it's always a good thing). And we are still maintaining reliability with the car.