I actually enjoyed the thought behind these events. Please bring them back at a later time once you fix out the kinks. And please try more things like these events, they are a nice change from the norm.
I lie the fact that they tried new things but Boss Rush was stupid broken and needs to be redesigned before running again.
For BFF this should be like BOP but force us to play with specific pairs. The issue was they buffed too many new characters that a lot of people did not have leveled and or potentially enough covers.
By locking out 5* and saying creating teams you can say if you choose IM40 your other character is War Machine. You then make them level 270 regardless of tier or currently level. If BFF isn’t something like this it would just be 2X 5* or 5* and buffed 4* and not really the fun BFF it was suppose to be.
bff would have made more sense if the characters were only buffed while used together