So, pardons can very much apply before conviction or even prosecution. They may not pardon someone for something that hasn’t happened, but as long as there in office when the crime is committed that’s more a technical issue.

https://en.wikipedia.org/wiki/Burdick_v._United_States

After President Gerald Ford left the White House in 1977, close friends said that the President privately justified his pardon of Richard Nixon by carrying in his wallet a portion of the text of the Burdick decision, which stated that a pardon carries an imputation of guilt and that acceptance carries a confession of guilt.[6] Ford made reference to the Burdick decision in his post-pardon written statement furnished to the Judiciary Committee of the United States House of Representatives on October 17, 1974.[7] However, the reference related only to the portion of Burdick that supported the proposition that the Constitution does not limit the pardon power to cases of convicted offenders or even indicted offenders.[7][8]

Presidents can’t just ignore a law categorically (although they regularly do, e.g. DACA, DOMA, etc.) On the other hand, presidents can certainly decide not to prosecute a particular entity under a particular law. That’s the heart of the executive power versus the legislative power.

Here, Congress wrote an extremely specific law that applies basically to one company. Which isn’t impermissible. But it’s also not clear to me that Congress can insist on immediate enforcement of that law without crossing effectively usurping the executive power and directing the President to prosecute a specific company at a specific time.

Similarly, one of the reasons the president has a pardon power is because he doesn't have to enforce those federal offenses. E.g. imagine that a president without pardon power instead offers "plea deals"/settlements for a $1 fine or concocts vacuously lenient house arrest enforcement.

The original constitution basically accepts that there is very little you can make a president do, and it instead formalizes what would otherwise be a gray area (it does have plenty about what he can't do). Some of this has changed over time especially as the judicial branch has granted itself more power.

You could obviously create a far more functional system but it would probably be far less stable. The reason you have all these checks and balances, from top to bottom, is that the Founding Fathers were obsessed about the risks imposed by both a tyranny of the majority and a tyranny of the minority. And non-enforcement of something effectively comes down just a continuation of the status quo, making it difficult for any group to [openly at least] impose their will on others.

They even have broad immunity while conducting official acts up to and including breaking the law. https://en.wikipedia.org/wiki/Trump_v._United_States_(2024)

“Trump v. United States, 603 U.S. 593 (2024), is a landmark decision[1][2] of the Supreme Court of the United States in which the Court determined that presidential immunity from criminal prosecution presumptively extends to all of a president's "official acts" – with absolute immunity for official acts within an exclusive presidential authority that Congress cannot regulate[1][2] such as the pardon, command of the military, execution of laws, or control of the executive branch.”

As to upholding laws passed by Congress--just two days ago, Biden did his last round of student debt forgiveness, bringing the total up to $188 billion.

I’m not trying to “both sides” this. I’m just saying that the standard you’ve articulated for how promptly the president needs to act on a law like this isn't the standard we apply in practice. The government tries to reach deals like this in lieu of enforcement actions all the time.