Normaly, distributing ROM hacks for NDS ROMs involves an XDelta patch applied to the entire ROM. 3DS hacks usually involves tedious ROM extraction and file replacement. Patches applied to the ROM as a whole do not support multiple regions of games, and tedious ROM extraction and file replacement is a chore. DS ROM Patcher aims to fix that: a single easily-distributable zip file contains everything that's needed to apply a hack to a ROM. The supported input and output formats are the same as in my .Net 3DS Toolkit: 3DS, CIA, Hans, and Luma Layered FS.
Instructions for creating and applying hacks can be found at the GitHub Readme page.
Requires the .Net Framework 4.6.2.
Download:
GitHub