Simple multi-mod support where people can activate multiple mods that affect the main campaign at once, instead of requiring people to merge mods.

Unlocked main campaign that isn't blocked by developer rights. You can't edit existing quests or creatures in D:OS except by editing their stats.

Fix "Reload stats," and make the "cheat" commands work.

For the love of muffins please make undo work for terrain manipulation. Also, a bigger change, but being able to select terrain and copy and paste it or move it somehow would be awesome, though I could see that being difficult. And if that's possible, then "terrain prefabs" would be really useful. Like, you could plop down a meadow with grass and flower meshes and good looking dirt and grass textures. More prefabs in general always help speed up level design.

Standalone mod template that contains the important scripts and everything set up for modding.

Let us edit and add talents. And an in-editor way to edit character or item stats would be cool. More freedom on the kind of stats that can be tied to items would be nice. And the ability to add new item types (I wanted to add an item type above legendary, but couldn't figure it out. Seemed possible, but just wasn't able to get it.)

Do you just want ideas for the engine itself, or for how Larian could help the community in general? Thoughts on the latter (I can delete these if you want this just for the engine.)

Both video and text tutorials. And for longer videos, marking the times for when you talk about specific things can be useful for referencing later. Also, filling an editor wiki with detailed information could be really useful.

I think doing a modding contest with prizes would be a great way to motivate people. You could have a contest for standalone mods, and one for best mod for the main campaign (maybe best added quest? And/or a best gameplay mod.)

One final thought: I think the most accepted spelling of "one who mods" is "modder." Just putting that out there :P Thanks a bunch norD!