I hadn't played Payday 2 for almost 3 years and returned to find many updates had been made (why would you release u240.3).
However, these changes kind of ruined the game, particularly Crime Spree - my favorite game mode. It is still playable nonetheless but it's.. pointless.
A 100-level catch-up bonus limit was introduced, which really took away the entire purpose of Crime Spree after u200.
After u200, crime spree was only used for the catch-up bonus in order to gain a lots of resources but primarily money and continental coins.
So yeah, it basically died entirely with the addition of bonus cap.
Like let's be honest low crime spree sucks, it isn't fun.
It's not difficult, it's not challenging enough so you might as well just not play it at all.

About the mod

Well, this mod brings back the old catch-up bonus calculation,
which was 3.5% of the difference between yours and hosts spree,
letting you not only get high spree again like in the old times (at the same time fulfilling the "catch-up" purpose)
but also obtain those amazing rewards.

This mod is only required by the client for it to work.