You cannot change the suspension independently. Putting the car in comfort mode makes the suspension "comfortable". Putting the car in sport mode puts the suspension in sports mode. You can go into the adaptive settings and say that if you are in sport mode you don't want the suspension changed with the sport mode change. Why anyone would choose to do that is beyond me. If what you are looking for is independent control of the suspension independent of the driving mode, that does not currently exist in i-drive.
I don't provide lease/finance advice via personal message, so please don't PM me asking for personal assistance with your lease. My time is valuable as is yours, thanks.