I'm not sure how this could be possible, they should agree to another new set of rules which will make them comfortable in the fighting. As we all know, boxing and UFC is completely different, there's not much to worry about Manny Pacquiao as boxing doesn't have that much freedom to hit, and boxers are already trained for that. But for the side of Conor, I don't want to happen what his fight with Mayweather, he is literally applying UFC rules.
Perhaps, rules should be clear to have an exciting fight. I'm sure Manny Pacquiao is not making this with money as his top priority, as I have heard before, he's gonna do it for a cause and that is to help the people.
Conor knows the rule of the boxing, he would not get a license if he does not, and this is not his first fight, we saw him fought Mayweather so I'm sure Conor would know how fight, it's just that his skills is at a lower level compared to Manny Pacquiao, and with that said, he would not win against Manny Pacquiao.