One,
It MUST NOT be suicidal.
Nothing in said reform can put the officer at unnecessary risk to their life. You won't find officers you want who will follow it. You'll just find officers that will lie and falsify about it and prosecutors who will nail anyone they catch, not anyone conducting themselves wrong.
Two,
It MUST be consistent.
The ROE of our military during GWOT shifted with the political winds, to a tune called by the 24-hour news cycle. That CANNOT be allowed to happen with whatever statutes we end up in. Any needed changes must be examined, tested, trained, and THEN implemented.
No officer we want with a badge will work under conditions where one political decision will turn the legit action they did yesterday into something that will see them imprisoned tomorrow.
Three,
It MUST stand alongside our scrutiny of self-defense.
Right now as regards to legitimate shootings, there's a massively lopsided law and precedent disparity between the citizenry and the police. The badge should hold an officer to at least an equal standard, if not a higher one, not less stringent scrutiny.
Four,
It MUST be publicized to hell and back.
The proliferation of body cameras proved that having video doesn't mean shit if you don't know what you're watching. The public needs to be informed about the honest truth of deadly encounters to the police and what they entail. And by now we know damned well they're not going to get it from the press. Whatever it is, it needs to be known better than "just say no" or "only you can prevent forest fires. That's the level of publicity that needs to happen here. Nationally funded PSA's and such.
And that doesn't even get into the state and local political reforms that have to be enacted in order to make police reforms even feasible. The use of police as a revenue source is a real big turd in that punchbowl. And floating next to it is the rapidly growing segment of the population that simply cannot afford any encounter with the police.
It keeps on going.