The structure of Frontlines doesn't lend itself well to such a mechanic, I don't think. Battle High is too strong of a deciding factor and the demerit on death means it's easy and common for a team to bleed a ton of points in the closing stages of a match. This, I think, is one of the other reasons that even a well-intentioned argument to remove rewards from losing is a non-starter - there are plenty of matches where finishing third place is the result of a coinflip determination from the #1 team going after free kills.