I would argue mod increases are now predetermined (open to manipulation) when they are obtained, and not completely random like before. I don't have a huge testing sample, but I have a lot of interesting results so far. I believe this was done with the increases coming after the leveling. For example, if you increase an newly obtained purple mod, several times my mod increase happened only in the 4th spot. I believe mods are now really open to being manipulated specifically around speed. It would be easy to do a formula to look at your inventory or the mod inventory averages and have a specific algorithm to weight the increases from the very beginning. At the very least I believe when you roll for an increase it's already been determined for the moment you farmed it, whether it was random at the time, or not.