I used the Party Mode in the 5-person dungeon and found that there were some problems that needed to be modified. Like:I wanted to follow the MT without entering a name. I wanted to stop following the MT in battle for manual movement. I wanted to ride where I could ride and so on. But I didn't want to re-implement all the party functions. I wanted to make changes based on the existing foundation. How to do it?

You can't. The party product code is not public, but Droidz has posted the grinder code so you can write your own products. I've also released a free party plugin you can take a look at.