investigate modding preloaded resources in 4.5+

this was added in 4.5

> [Troubleshooting](https://docs.godotengine.org/en/stable/tutorials/export/exporting_pcks.html#troubleshooting)
If you are loading a resource pack and are not noticing any changes, it may be due to the pack being loaded too late. This is particularly the case with menu scenes that may preload other scenes using [preload()](https://docs.godotengine.org/en/stable/classes/class_%40gdscript.html#class-gdscript-method-preload). This means that loading a pack in the menu will not affect the other scene that was already preloaded.
>
> To avoid this, you need to load the pack as early as possible. To do so, create a new [autoload](https://docs.godotengine.org/en/stable/tutorials/scripting/singletons_autoload.html#doc-singletons-autoload) script and call [ProjectSettings.load_resource_pack()](https://docs.godotengine.org/en/stable/classes/class_projectsettings.html#class-projectsettings-method-load-resource-pack) in the autoload script's _init() function, rather than _enter_tree() or _ready().

to me it sounds like this means all mods should just be able to properly replace preloaded things now. without any extra changes from our side.

just needs testing and a docs update