And also sense Bocc can't deny an OOC challenge does that mean that Eric can't deny an IC one? That only seems fair to me. I just want to be sure though.
Neither the challenger nor the host are supposed to be able to force anything on each other in that regard:
The host and the challenger, and ONLY the host and challenger, determine the nature of the challenge. BOTH decide if the match will be an IC Challenge or an OOC Challenge.
Among the negotiations that may be made at the very beginning of the match, whether it is IC or OOC or not is one of them. It is disallowed to have mandatory deathmatches, but that does not mean that you cannot have deathmatches.
The two will make all arrangements for when the match will begin and where. Should the Jinchuriki ignore or refuse the invitation(s)-with no reason given- 3 times consecutively, you may report it to other Jinchuriki. Subject for such an event's invitation, for proof & reference of a challenge, must be titled: (Number of tails) - (Name of Jinchuriki); the body of the message may be as you please (though manners & politeness would of course make things much smoother).
This suggests that a host can in fact refuse a biju challenge. However, a reason must be given, and it is reported to other jinchs (counselor flaw atm, but it's in there) if the challenger feels that the reason was not valid. If the "others" view the uncompromisable position that one host and one challenger cannot decide on whether it is to be OOC or IC, I presume a middle ground is instead attempted on the two in order to flesh out a solution.
If one still cannot be made, then considering the counselors in that situation, the challenger would likely then have to compromise on something in order to carry on with the challenge. The audience are jinchs, who are not going to want to be forced to do IC or OOC, so it would be uncanny of them to vote in that specific situation that the challenger gets their way, especially if another challenger down the list is willing to at least compromise on a give-take basis. So in practice, that would be a very bad thing to not be able to compromise on for the challenger.
So as far as your question Kirk, I can and I can't. I can deny all I want, but if it is deemed unreasonable (which would be practically the same as not giving a reason at all under that rule, unless that rule is made ONLY for if the host gives no reason to the challenger about why they refuse, in which case we are back to where we started with this thread in that the host does in fact have more welding power on the match's characteristics) then it would have to be taken to some court in order for a decision to be made.
A provision for such hasn't really been set up, obviously, especially if it is a jinch decision. While all jinchs have minds of their own, a cry of bias is not entirely unfounded, since we have our interests as fellow hosts as well to consider, though whether that affects our decision or not is up for future debate.
In the end, I say that if the challenger and the host cannot come to a compromise over something as simple as IC or OOC, flip a coin. Roll some dice. Because if the challenger attempts to get other jinchs to force other jinchs to do IC or OOC, they are probably not going to win that fight.