Merged the threads.
I would generally discourage discord as a platform for this sort of thing -- no discoverability (that you, presumably as a self selected, motivated and technically capable individual have to do a cry to the void...), annoying to share, takeover risks when someone gets bored, discord up and going pop or deleting it because moderation... It has all the same problems for individual projects (translations, restorations, specific goal balance) but they happen often enough in private anyway.
Xeno has a bit of a following, though xenogears and the chronicles spinoffs get most of the focus these days, with some xenosaga in the dim and distant past.
https://www.romhacking.net/games/953/
https://www.romhacking.net/games/4632/
Most of the hacking work I have seen for xenoblade chronicles (I will try to skip the yawnicles comments today, though it being a niche game franchise does work against it compared to the generally adored Square (Enix) in the 8 through 32 bit eras which do get all the tools, hacks, big communities and more besides, could even be something you correct with hacks) specifically other than the shop editor referenced (
https://www.romhacking.net/utilities/1645/ ) was more for handling the Wii version and its texture replacements/upres and frame boosts in emulators (which often had a turbo mode employed as well).
If you are already familiar with reverse engineering, especially if the point of being able to use a debugger and muddle through some assembly (powerpc is a bit odd if you are more ARM or X86 but nothing too drastic) then game stuff is nothing too radical, though some of the workflows might be more strange.
To that end if you wanted to start by making a raft of cheats, basic infinite life through stats changes, growth rates (chuck a shift in exp or whatever gains and yeah) inventory and more exotic that would probably be wonderful.
If you take said stats cheats and make it at least able to be edited with a hex editor then so much the better, a python script or something to render it a nice GUI tweak tool then you are now ahead of far more popular franchises.
If you want to fuzz a game or two and figure out if there are any developer secrets , leftover content (make weapon cheats, find normal game limits and exceed them to see if last normal value +1 or 255 and back), play as boss options (granted that is more cheat), unused textures and such then that can generate interest in and of itself.
Map editors are a bit more involved usually, though if you can figure enemy placement, drop placement and some more general stuff there then you can get some people interested.
Instead of map editing I usually find more it interesting to fiddle with systems, be it editing them with an eye to rebalance (or hard modes) or being able to demonstrate a nice
https://www.dragonflycave.com/mechanics/gen-i-capturing equivalent.
Text editing is less useful when things have already been translated to English but figuring out the font and text handling (Wii on up saw some fairly interesting engines beyond basic table
https://transcorp.romhacking.net/scratchpad/Table File Format.txt and pointers).
Combine some of the previous for a boss rush mode, or just challenge mode and so much the better.
E and XC2, through a Github.io database, but sadly none yet for XC3, which is unfortunate. 
