I definitely think you should straightforward tell your daughters that going forward you will not be coordinating visits with their dad, the ball is in their and his court, or state whatever your new stance is that you are comfortable with.
Just say, it’s really hard for me each year, inviting your father over, never hearing whether he’s coming or not (or whatever) so I’d like you guys to take over coordinating your visits with him. It’s fine with me if you invite him here, just let me know you did, I just won’t assume he is or isn’t coming. I’m here to support you but it’s time for you to take over making the arrangements
My sister does invite her ex to big family gatherings such as Christmas and reunions, sometimes he comes, sometimes he doesn’t, but she just invites and that’s it. If I ask if he’s coming she’ll just say, I invited him, I don’t know if he’s coming. Some of her (very adult) kids stay in touch with him, some don’t.
Along with my kids’ dad cutting them off, most of his side of the family had very little to do with them. I used to make a trip once a year and visit the aunt and uncle, and grandmother, that were in our state. None of them ever made an effort to invite the kids to stay overnight, come back for another visit, etc., even though we regularly read about interactions with other grandchildren in Christmas letters.
When the kids were in their late teens, I told them I’d done my part, it was now up to them to make the effort to continue the relationships. The very last straw, when I cut off my own remaining minimal contact, was when I had to read about a trip Grandma took that brought her literally 3 blocks from my house but she did not call or stop by. By that time she had a great grandchild here she could have seen for the first time. All those years I had driven my kids hundreds of miles so they could know their grandmother (their father, her own son, would not do this) and that was the thanks I got.
The kids kept up varying degrees of contact which seems to have actually improved a little over the years. Grandma never did get to meet that delightful greatgrandchild (her son, the child’s grandfather, has never met her either–now 18 years old).