Por si os interesa, para desbanear la consola sin tener que usar 2, parece simple:
1) Open Decrypt9 on your 3DS, go to SysNAND Options>System File Dump and do the two following procedures: Dump LocalFriendCodeSeed_B and Dump movable.sed;
2) Now open your SD root on your pc, and get the 2 files you just dumped in the files9 folder;
3) Open HxD (download it for yourself) and open both movable.sed and FCSL_B;
4) On movable.sed, copy everything except for the first 8 bytes and the last 40 (for dummys, use the indexes, you can start copying from row 00000000/ col 08 until row 00000110/ col 07);
5) Open LFCS_B, press ctrl + A, then paste your code (it must be and different code than before, if not, see step 7)
6) Now just go to Decrypt9 again and inject back the LFCS_B that you edited and you're good to go.
Si necesitáis que traduzca lo hago, pero creo que es bastante simple