https://www.reboot.ms/forum/threads/supermysterychunkhax-per-powersaves-11-0-10-7-10-6.2408/
Supermysterychunkhax powersaves files, tested on 10.7 sysnand and emunand + 11.0 tested on Luma3ds EmuNAND. All the files are from user ecos.
I have a DSTWO, DSM, a PSMD cartridge and a working 10.7 3ds. I've already done the modding needed to get the 3ds cart to fit into the DS Lite, if that helps. I can edit the PSMD savefile, so if a save works, then it should work for powersaves too.