At worst it'd brick the DSi mode, in which case you can simply restore a nand/partition backup.
I doubt this will work since a DSi nand is a full image and not a partition, but you're welcome to try provided you make a nand backup first.
With that im able to acces System Setting of DSi if i format it that break all the apps + twl mode broken if you update that will make an error at 50÷ so idk