(Ex Gratia) Can an executor settle a fee dispute with just me directly? England

[noonenoname2]

I potentially have a fee dispute with solicitor executors regarding their fees for work done.

The other beneficiaries have signed a waiver releasing the executor from liability I have not signed this.
Is the executor allowed to make a settlement with me directly regarding my fee dispute?

I'm not sure if it would be considered unfair to the other beneficiaries if they made a settlement directly with me and excluded them?
I was told the following but I'm not sure if it is accurate:-

If the other beneficiaries have signed a waiver, they have legally "affirmed" the accounts. In the eyes of the law, they have said: "I have seen the bill, I agree it is fair, and I waive my right to challenge it." Because they have waived their rights, the firm no longer owes them a duty to reconsider those fees. However, because you haven't signed, the firm still has a potential liability toward you.

The "Ex-Gratia" Loophole: The firm won't call it a "refund to the estate." They will call it a "payment in full and final settlement of your specific complaint." This is a private contract between you and the firm to stop you from going to the Legal Ombudsman. It doesn't involve the estate accounts at all.
My other question is am I in a stronger position to dispute the fees if the other beneficiaries have signed a wavier of liability for the executors? Or am I in a stronger position if they have not signed it or is it neutral?

I suppose if they are allowed to settle with me directly it's easier to get a settlement if I am the only one that can ask as it's less money the executors have to worry about refunding.
But if they are not allowed to offer a direct settlement it might be better or neutral for me if other beneficiaries haven't signed also?

[atticus]

Yes. You may pursue your claim.

[Frank1]

If you make a successful claim and the executor is ordered to reduce his fees, the estate will benefit from this reduction.
As such the other beneficiaries will also benefit.

Beneficiaries can waive their right to sue the executor for negligence but not their legal right to have the estate managed properly and for the executor to charge the estate agreed or reasonable fees.