This post is meant to list some of the current possible improvements to our understanding of the game. Much of this is easily testable; I just haven't had time to fire up an emulator.

Post proofs if you have info.

Combo Kill Multiplier: We need to figure out how the multiplication applies. Getting a multiplier on boss fights could be an enormous boon to BP progression if it can be done in a time efficient manner. Does the boss need to be killed after the initial person is killed to get the multiplier or does it just need to be one kill in the chain?

Combo BP Bonus: Do kill combos increase the base amount of BP per kill before multiplication?

Enemy BP Values: Tracking each enemies' BP value on kill.

Damage Values: Tracking the damage values of each players moves both singularly and in a combo. This can be tested with controls in training mode.

Power Stat: Testing what the Power stat does exactly. Does it affect only basic moves? Does it affect throws? Does it affect learned moves? Does an increase to Power stat correspond to a direct increase in damage per hit by the raised amount or is there a proration / decimal multiplier on the Power Up stat per move?

Move Set: Refining and recording the effects of moves, particularly damage values, bouncing direction, interesting attributes, and potentially frame data to maximize DPS / safety.

Bouncing: Determining how bouncing damage is calculated. Is it based on the initial hit that caused the bounce? Is it a base value or base percentage? Is it modified by the Power stat?

Analog Button Moves: Basically need to find out how "hard button presses" work. If it is just holding the button a certain number of frames, then it should be fine. If it isn't, then we would need to figure out what we wanted to do about emulator since controlling which moves you execute is a skill linked to the combat system. This could be bypassed in emulator.

Stealth Section: Comparing time taken to complete a stealth section vs fighting. My early testing seemed to indicate fighting was faster or on par and led to an influx of needed BP. Needs verification.

Basically we just need to test thoroughly how it works exactly on emulator, and then try to duplicate results on actual hardware.

For BP multiplication, I've tried manipulating focus on characters by getting Echidna as low as possible, then creating a domino effect of one of the guards into her to get a 2x multiplier. While harder to pull off, especially with the targeting mechanics of The Bouncer, it could be considered easier than killing an enemy then trying to kill the boss immediately after.

The power stat definitely affects every move in the game, testing between G and S rank Sion, the basic punches, special moves and throws all have significant increases in damage. I've found Sion's triple high punch to be most effective with his move set in dealing the most damage in the shortest amount of time; an issue, however, is Echidna, mainly due to her having a smaller hitbox in defence mode, so it means the punches can occasionally miss.

Dogs and Kaldea work by doing the light-heavy combo with a low attack, but the issue, as you've pointed out, is that it seems to be difficult to gauge what is considered a hard button press.

Also I'm fairly certain the initial hit of a bouncing sequence is constant damage passed onto one another; thus, a far more powerful move that knocks an enemy into others is the key early on, but finding out what move does the most damage is necessary and what BP it requires.