because you added more code means you have more points of failure. it's amazing you can code for the 3ds, but you should know this as a general programmer that more code means more to fix. and as of what
@Xenon Hacks experienced, it seems like your sysupdater is FAR LESS stable than the normal sysupdater.
technically, you're right, of course, the more code you write, the more likely it is that you make a mistake, but the downgrading code is already working and wasn't changed.
he added hash checks, to prevent you from using the program with the wrong files, which would cause a brick right there. technically, that wasn't necessary, but its for the end user.
at the end of the day, it's still going to have to go through the 3ds's issues though. sometimes, memchunkhax initiates like it should, sometimes it doesnt. there's seemingly little one can do to change that.
and sometimes, installing a cia file will fail regardless of using the right files.
as far as we all can tell, this is as save as its ever going to get. a new entrypoint with more stable kernel access may or may not give us a more stable downgrade somewhere along the line, we'll have to see.
but for now, its a bit of luck and trying over and over.