fmil drama.. Should we just pay for our own rehearsal dinner?

So we don’t talk to my FMIL if we can avoid it about wedding things, because she’s been super nasty to FH (nothing new) and myself about certain things, not everything. It’s more of guest list, and anything else that would involve her family who lives on the other side of the country and has never showed any interest in her FH life now that they r older and have been living far away for 22+ years, but FMIL takes offense to literally everything which is why FH doesn’t have a good relationship bc if you don’t agree with her or do what she says you are terrible in her eyes. For content she also overstepped dress arrangements w my SIL but I have gotten over that quickly, even tho she tried to blame me as the reason to my own mother..
Anyways, my mother is paying for the majority of the wedding and I had a conversation about figuring out who we are inviting in person with the Covid guidelines in NY state and who we were going to cut to invite virtually since we have to cut 100 people for in person. FH and I have already cut people off our list which is nothing new we’ve been doing that since we got engaged, my parents have cut a ton of people off of their list (family friends who know both FH and I) and she told FMIL they had to cut the same number of people off of their list for the wedding. FH was talking with FMIL tonight and I walked in and when I got on the phone she brought up wedding stuff. Now last night after my mom and FMIL had this whole conversation about cutting people off of the wedding guest list to meet the Covid restrictions our state currently has, she tried telling my mom we would now need to also cut the rehearsal dinner guest list bc she is hosting it and I guess could dictate that. I called the place we’re having rehearsal dinner at and they said they have more than enough room to accommodate our initial guest list. Our rehearsal dinner guest list is your typical rehearsal dinner people, it also includes six of my aunts and uncles I’m really close with that my mother has told FMIL from the start a year ago that she would cover because it’s not someone you would typically invite to the rehearsal dinner. Now FMIL says it needs to be cut, when we discuss wedding stuff tonight I told her that it was really important to me to have them there, and she kept saying it wasn’t fair and kept going back to how she had to cut her aunts and uncles (FH greats) from original in person wedding guest list, even though she keeps telling me for a long time now that they probably won’t actually make the trip out here and show up to said wedding and why would they bc they don’t go out if their way to drive 15 min to FH Gma’s house to see him when he goes out to visit home state which us far from where we live and are getting married. Felt like it was an unfair punishment for me because of Covid and cutting wedding guest list that now my aunts and uncles who have been an integral part of wedding planning any huge part of my life growing up can’t come to this rehearsal dinner that they can be accommodated to and FMIL Doesn’t have to pay for. What do I do? FMIL said from the beginning that she would cover this dinner as part of her contribution to the wedding and was prideful in it, I tore dsyif if aunts and uncles can’t be invited to OUR rehearsal dinner, FH and I would just pay for it, but second I mentioned that it was a whole other hissy fit about it’s not about money but fairness and she’s paying for it. I also don’t want to tarnish this relationship with her because she is my FH‘s mother and although he knows how toxic she is, he still tries when he can and is close w siblings and future step father in law (my future that guy is like his dad), his parents were never married and the fact that we are inviting people to wedding not rehearsal, from his biological dad side is a whole huge issue too, even though he is super close with them. No pleading this woman! HELP! And sorry for the rant. I’m really giving up on wedding planning, I wish we had just eloped from the start