I looked at your other posts.. and honestly, I know you are trying to be a good partner to your BF.. but I think you are making a colossal mistake.  I see several red flags in your situation.

1.  Criminal charges... apparently both he and his EX have them?  Are these really the caliber of people you want to spend your life with. 

2.  His daughter is a handful and a half.. and it appears he has put big expectations on YOU to make it work.  Do not underestimate the stress that will be put on your relationship by an alienated teen with a bio parent that is likely interested in alienating both you and your BF.  

3.  It appears that this is a pretty fresh situation for him.  Not sure if you and he were dating prior to his split with his EX.. but ideally.. all this settlement stuff should have been resolved before you were on the scene..  So.. he rushed into a relationship with you.

4.  The guy is not financially in a good place.  He can't hold his end of the rope up.. you think you are being "there for him" and got his back by putting up YOUR money for HIS obligations.. but there are so many ways I see this relationship at risk.. that he could decide to walk away because he doesn't like how you and his daughter interact.  What do you think the odds are that you will be repaid when you are no longer his girlfriend.. shoot.. if he can't save a dime now.. how do you think he will be able to pay his share going forward and also repay you??? newsflash.. he can't.. and he won't.  empty promises..

This settlement is between him and his EX.  Their lawyers should be good enough to NOT miss things.. and if your BF is so dense that HE can't pick up on things like you caught.. that would be red flag number FIVE.. HE IS STUPID.

He should understand what he can and cannot offer.. what would impact his home.. and by association you.  You can discuss some hard boundaries but I don't think you should be there "in the room with them".  Maybe you could get his lawyer to let you sit in a nearby office.. and he can come out and go over things before he signs/agrees to the final order?

Again.. I think you giving him money is a bad idea.  I think you could do better than this guy.. too many red flags and your life is going to be full of drama.. so you are choosing the drama if you stay.

Don't go, it's not your place to be there. Wait in the waiting room for him. Please don't get into a habit of trying to fix his problems for him - they are his to deal with. 

I have never set foot in the courtroom for any of DH's court appearances, but I've supported him by going and waiting for him. 

Why are you paying for his divorce when in a prior post your said, "Afraid boyfriend will break up with me if his daughter and I cent get along." If you think your boyfriend may leave you because of his daughter, why in the world are you putting up any money towards his legal bills?

There is no need for you to be at the settlement conference, that is why he has a lawyer. This is between he and his ex, you have no legal standing and no reason to be there - especially if it is going to antagonize his ex.

Everything above, and why are putting up ANY money for this guy?

I think you're asking the wrong question.  The important question, IMO, is not whether you should be in the settlement conference with him, it's whether you should be with him at all.

As others have said, the red flags are flying.  You're worried he'll break up with you if you and his daughter don't get along, his daughter is a PITA, you're paying more than your share . . . .  IMO, the answer to the important question is NO.

The answer to the question you asked is also no.  I don't think you should be in the room where they're hammering out the settlement.  However, if you've already established that his lawyer is a dud, perhaps you could arrange with the lawyer (I wouldn't trust the boyfriend) to bring whatever is agreed upon to you in another room so you can review and sign off on it.  If you're going to be paying for the divorce and carrying the ongoing financial burden, you should definitely get a look-see to make sure your boyfriend and his lawyer haven't agreed to something you're not willing to finance.  And since you want to support your boyfriend, he'll probably feel better knowing that you're in a nearby room ready and willing to vet his agreement. 

As for you being paid back - I'll be watching for those flying pigs.  If I were you, I would not lend your boyfriend money, directly or by picking up his share of expenses, unless it's money you are willing to give to him with no expectation of seeing it again.

This is your BF's problem to deal with. Yes I get you want to be supportive but you are doing MORE than enough by financially helping him out. Stay out of this and whatever happens, let the pieces fall where they may. He's a grown @ss man and you shouldn't have to be holding his hand. Have faith that he can handle this and things will work out. 

No comment.

Have him take his phone in and call  you so you can listen in and text him with guidance if he or your lawyer miss anything. 

Out final court hearing during our years under a Custody/Visitation/Suppoort CO was a telephone hearing. One again I was names as not a party to the case and was not allowed to "participate" though I had been raising my SS for 9 years at that point. So I did not "participate" at least as far as the Judge could tell.

So, we put our end of the call on speaker and I stood behind my bride pulling documents from our volumes of records and handing them to her with highlights for her to use to attack SpermClan bullshit and box in the Judge.

Ultimately the Judge ruled heavily in our favor.  So, if you want to be involved, get innovative and have your DH carry you in to the mediation in his pocket and you text him you rinput an guidance.