I asked him already.
He decrypted and extracted Content1, unpacked the Manual.bcma with a tool that can Handle DARC-Files (arc files with "DARC" header) and he uses the Dev-Tools to create his own bclyt-files.
I asked him already.
He decrypted and extracted Content1, unpacked the Manual.bcma with a tool that can Handle DARC-Files (arc files with "DARC" header) and he uses the Dev-Tools to create his own bclyt-files.
He's using the latest one, it seems.
On his Twitter Account he wrote that he's using CTR_SDK-11_2 for Undertale3DS, probably he has CTR_SDK-11_4 already.
EDIT:
Okay, he wrote something about this on Twitter