Hey Kryzeth, the 9.4.0 update added keybinds for cycling through the machine sizes (as well as a whole bunch of awesome changes).

The first and most simple bug I found is missing localization text for the keybinds in the Controls settings window.
The text reads: Unknown key: "controls.machine-size-cycle-down" and Unknown key: "controls.machine-size-cycle-up".

Though the more critical bug is that the keybinds don't work for a handful of machines, including:
Steam Engine
Fusion Reactor
Fusion Generator
Advanced Mining Drill (space-age.bigminer)
Foundry
Recycler
Biochamber
Oil Refinery
Chemical Plant
Centrifuge
Electromagnetic Plant
Cryogenic Plant
Lab
Biolab
Lightning Collector
Heating Tower

Notably, if I have a mini/micro ghost or item in my hand then use the keybinds, the cursor is set to the default (vanilla) size of the ghost/item.
Also, when using the pipette tool to pick a ghost of an existing building, it puts the default size item on the cursor. Though I think your changelog suggests that is the correct behavior now.

Please note that I am running both mini machines and micro machines (and their dependent settings and library) mods.

Thanks for the awesome mods! Please let me know if I can help gather more info for you to fix these issues.

Sorry, I didn't think to check the tech tree after updating my existing save... I guess the update to 9.4.0 reset all the mini/micro technologies and the keybinds only support machines that have the tech unlocked.

So perhaps this is less a bug and more a request for a setting that allows you to select the different sizes of machines without having them unlocked, since there is no way to get to the mini/micro versions via the factoriopedia anymore.

Specifically, my play style is to set up a factory via blueprints before actually building it, and if I can't access the mini/micro machines even in ghost form then I can't plan the factory layout until I unlock the research.

So there are two bugs: the research gets reset, and the Machines drop as themselves settings don't work.

Good catch with the locale thing, I completely forgot to check that part.

The second part is definitely a bit more of an issue, since I don't know of an easy way to prevent bots and space platforms from building the ghosts of mini/micro machines (I guess this could be considered an exploit, since I think blueprints would also bypass this restriction) using the vanilla machines that are already available.

Oh, and technologies were added for machines that were previously being unlocked by trigger techs, which includes the steam engine, chemical plant, oil refineries, and I think all of the space age buildings.

I should be able to add a setting to remove the technology restriction at least.

EDIT: I completely neglected to check the non-building settings; I removed the functionality for most, if not all, of them

Aha, okay so there are new mini/micro techs for all the trigger-based techs. I think the mod description is unclear about that, or maybe the tooltip for the Enable Tech Tree setting is misleading as it implies that trigger techs will unlock the mini machines as well.

Implemented several informational changes in v9.4.1

Specifically removed several settings that were no longer being used. The tech tree is always enabled, as it is used as the check to allow cycling to the various sizes, and prevents placement of resized machines if the technology has not been researched.

Machines drop as themselves and Costless Recipe Conversion are no longer needed, as resized machines will always drop as vanilla machines (and are placeable from the vanilla machine); thus removing the need for a middle man, and allowing the user to seamlessly cycle between the various sizes, without getting stuck with an item at a particular size.

I've also added a message for save files that are updating from a 9.3.x or earlier save, that should clarify the most important changes (this won't apply when updating from 9.4.0 to 9.4.x)

Final thing, I'm not sure if I can fix the pipette issue; that seems to be a vanilla thing, as in, that's just how it works with the placeable_by field, which is the same reason a curved rail will put rails in cursor, or a customized pipe from Flow Control will put a standard pipe in the cursor.

Excellent, and awesome changes! Thanks so much!