i haven't tested yet (merry christmas) but the bomb used in smash animations not disappearing on contact doesnt sound as though to be too big a deal. In addition to the fact it maintains the clarity of where the hitboxes are, which could be important in certain scenarios such as doubles or for example hitting a peach's turnip while the move's hitboxes are active after just having hit her, Link's bomb has its own mechanic that deals mild fiery damage to an enemy without the bomb disappearing, so the design is not totally baseless. But, I haven't seen it for myself ye,t so these (in)observations could be without grounds.
edit: the bomb choice deal actually sounds pretty cool, though. it might be too easy to hit an enemy with the bomb, making it a safe gamble, but since i would imagine it still takes a long ass time to charge the bomb and not having the bomb at all really makes your recovery suck(? havent seen yet), i dont know how it'll work out. It sounds as though bomb charge will be almost uniquely determinate of bomberman's momentum; the extremes of which in their current states of tuning make or break the character respectively. More actual admissible feedback once I see for myself