This article is helpful. Anne P. Mitchell makes clear that the slush fund and the immunity agreement signed by Todd Blanche were ruled illegal by the court weeks ago. So all the back and forth about getting Blanche to sign something stating that the slush fund is dead; pointing out that what Blanche did sign is not legally binding; and pointing out that what he signed didn't kill the immunity agreement is all moot.

Anne includes a link to the amici brief. It's instructive reading.

The court said the agreement- slush fund and immunity- are not legally enforceable, and are not to be used in any way. (See photo) The judge also ordered sanctions against lawyers who participated in bringing the spurious case against the IRS.

President Trump, 3 weeks after the ruling, is appealing the sanctions order. I believe he is only appealing the sanctions - not the ruling that the slush fund and immunity agreement are illegal and cannot be used.

Anne also points out that the court asked amici to defend the IRS in this case, because the DOJ isn't. Which is the DOJ's primary job description.