Version 1.8.0:
A set of ID tools has been added to OptiPloy to allow more flexibility over what gets imported, and how it gets imported Tools are available in the Outliner or Properties Context Menu
You can now set how IDs are treated in the import process. The three options are:
No major logic tweaks
easy_message_board code adding unwanted functionality to OptiPloyNo changelog for this release.
Storage Benchmarking
Next to the spawn button, you'll find a button with a disk drive icon. This tool lets you see how much space you save using OptiPloy to import a specific object or collection, compared to appending.
The behavior of this tool should be noted. It requires a blank slate to work, and will delete your progress if done in a .blend file with no filepath. Otherwise, it will automatically save and re-open your working file.

No changelog for this release.
Tweaked how indirectly linked objects and collections are handled in the "FAST" importer for increased stability of rigs
Tweaked the "FAST" importer to be much more resistant to hierarchy loops.
I know I've done this two times already about the new importer, but I have much more faith in this. The fixes revolved around getting one of @zayjax_'s (<twitter) rigs to work, and I accomplished that. I also sat down in a call with him and had him try this new version, it worked with every single one of his rigs. First-hand witness, I swear. Thank you zayjax!
Re-wrote the importer (again) for zero errors during importing. OptiPloy no longer takes advantage of the bpy.types.ID.override_hierarchy_create function, and instead uses its own functional approach that produces the same result without any of the overrides referencing a hierarchy root.
Previously, errors would occur when the hierarchy was disrupted through localizing data-blocks, which was necessary. Overrides are now given in a specific order according to how the import is composed.
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Added more functionality to the .blend (and now folder) multi-tool.
Fixed a bug with the post-optimizer, involving instanced collections