And do you regret signing it

No one seems to be addressing that, yet.

wearily,
Bright

... defined it as "on SSI and needs help managing finances." Even the ACLU didn't like that one.

https://www.federalregister.gov/documents/2016/12/19/2016-30407/implementation-of-the-nics-improvement-amendments-act-of-2007

You're right. It was not very good but apparently the best Obama/Dems could get through unprecedented obstruction from GOP/NRA. It involved mental impairment to receive disability benefits. The intent was good but I doubt it would have had any effect on preventing mass shooters from getting weapons, most of whom are not on disability.

NRA has been deliberately weakening the type and amount of data going into NICS since always. This rule was finalized in December 2016 and got Trumped just 2 months later and accomplished little or nothing.

Trump and the GOP are pretty shitty in many ways, but not because of this.