First, I admire that you're contributing for the DSi community by making a tool to uninstall unlaunch. But I have to say with this tool, it's somewhat unsafe because it's involving nand flashing (which is always dangerous if you're not careful) with a unstable version of FWTOOL @realWinterMute doesn't anyone to use as he proved that it can damage your console slowly. I'm not saying to close this down but to at least wait for @realWinterMute to release a stable version of FWTOOL with a proper setting of restoring your nand.
On the contrary, he does appear to be working on a safer solution. Here's an excerpt taken from the Flipnote Lenny page:
Please note: fwTool currently has no NAND restore options for the simple reason that it’s horrifically dangerous atm. I have some things in progress that will be safer but, for now, please don’t use any of the forks that add dubious NAND writing options.
I believe the same was said about the 3DS scene, like how some users we're waiting to get homebrew access and CFW on a certain FW version. That was the past, though.
Almost every scene are big waiting games.
It is also my decision, as I've wasted enough NAND R/W cycles on my DSi console already, just by flashing a whole NAND image.
I don't want to risk wasting more of them, as I've heard that flashing the NAND to the console enough times, would render the DSi unusable (or bricked).
The NAND chip of the DSi is way older than the ones on the 3DS and Switch.
WinterMute tends to do things properly rather than quickly. It took a very long time for citro2d to come out after all, but it's out now and to my knowledge it's the best 2D graphics library for the 3DS.