downgraded one new3ds (fw 9.9) with sysupdater and another one (fw 9.9) with safesysupdater.
sysupdater is a little bit stressful - i had to try a lot of times to get it run.
safesysupdater is nice - just needed 2 trys to get it working.
thank you some much for your work! both consoles were...