GIST - Genuinely Intelligent Soul Trap

The problem of the underfilled soul gem: Old as Skyrim itself, yet none of the previous solutions were quite perfect.

Acquisitive Soul Gems throws small souls away to prevent under-filling larger gems. But that is removing a feature from vanilla, instead of fixing it.

The solution:

Small souls should be allowed to underfill a soul gem. But if a bigger soul comes along later, it should be able to push that smaller soul out of its way. This way you aren't missing out on small souls or big souls. If you have room for a soul, you will capture it.

Optionally, displaced souls are allowed to move to a smaller available gem. Example:

Grand Soul Gem (Lesser)  +  Lesser Soul Gem (empty)  +  new Grand soul

-->     Grand Soul Gem (filled)  +  Lesser Soul Gem (filled)

Optionally, if there really is no gem large enough for a soul, it can also be allowed to shrink to fit in a smaller gem:

Greater Soul Gem (Lesser)  +  Lesser Soul Gem (empty)  +  new Grand soul

-->     Greater Soul Gem (filled)  +  Lesser Soul Gem (filled)

If multiple souls are captured at once, the algorithm is multithreaded to handle them. It prioritizes them by size, finding a place for the largest soul first then moving to the smaller ones.

Lastly, there is an optional system to allow your soul-trapping abilities to level along with your Conjuration (or Enchantment) skill. All of the features of this mod, and also the ability to capture souls of a certain size, can be set to unlock at a certain level. Each feature can be configured separately. (This system is disabled by default.)

Notes:

[]Any soul gems that you've filled before installing this mod will be treated as empty by the algorithm. This is an engine limitation. Use or sell those gems before you enable this mod. (Gems that are pre-filled when you find them will be fine, and Azura's Star / The Black Star will be unaffected.)

[]Configuration works through an MCM menu. You need SkyUI to use this. If you don't have SkyUI you can still use the mod, but you need to use console commands if you want to change any options (see FAQ).

[*]Azura's Star can o