There is a reoccurring pattern in children (and cats & dogs) that when given a gift inside of a box, many frequently are more interested in the box than the gift. Thus the idea of a treasure hunter mech. One that is interested in finding and opening boxes (i.e., chests), but not caring about what is inside (e.g., its all unimportant junk). Its the adventure that matters. So then the process of opening the chest is what gives them the reward, in this case random buffs.
Chest in Time: Fair point. Most likely there would be a shot clearing wave on leaving the chest.
Need for speed: Boss cheese, Still okay with it
Radar - Would be somewhat complicated to do.
SPEED - Given the universal hatred for the Limter Removal, this one will not be appreciated.