The official ScummVM codebase was updated with what was necessary to make builds for the 3DS. The port was broken/uncompile-able for a number of years, at least since DevkitPro's upgrade to pacman, but should be back on track since November 2018.
ScummVM has one frontend as far as I'm aware, however it has backend ports for every platform it supports (3DS, Android, SDL, PSP, WII...).
This usually means that the code must be cross-compiled (using a compiler and libraries for the system you want to compile for).
As a quick and dirty explanation, ScummVM has certain core calls that need to be translated to the system-specific equivalents in order for all of it to come together, and that's roughly what the ports are.
This means you can clone the master branch from the official
Github, and you could follow the instructions in the backends/platform/3ds/README in order to make your own build.
There aren't official ScummVM daily builds for the 3DS likely because they don't have an active maintainer for the system (a person who could look at port-specific bugs on a regular basis), or more importantly because it isn't possible (or wasn't when I last looked at it) to create a 3DS build that includes all the engines, because of space restrictions.
If the port supported dynamic plugins this would have been possible, but as far as I know it never did.
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In any case, if you took the most recent ScummVM code and follow the instructions, you should be able to compile it as-is.
No further "hacking" would be required unless an update to the core code or configure script has somehow broken the 3DS backend. I don't think that's the case today, albeit I haven't compiled it in a while.
This thread (that we're talking in) is about making your own game forwarders for individual games. That's not exactly part of ScummVM as it stands today.
So if you would want to run ScummVM through HBLauncher or as an app from the Home menu, you could just compile from the official ScummVM source.
However if you would like to have a nice icon, banner and potentially music on the Home menu for every individual game you have, you should use
@MrHuu's method supplied in this thread, in addition to being able to compile the source code.
(from memory, I believe with MrHuu's fork here you might enjoy a slight performance boost for resource-intensive games)
Even if you updated your tree with the most recent code from the official ScummVM master, you should still be able to continue this method to create game forwarders.