The description boasts that it has a "whopping 750% power cost" with enough modules.

Which is like ok, so instead of the assembler eating up 400kw, it will eat up 4mw. My god, however will my power grid be capable of handling such a burden? That's like 2 entire steam boilers. I'm only saying this because I'm looking for a proper deterministic quality mod, but so many of them seem to think that forcing you to construct an extra boiler is the be all end all of penalties.

At the level where most people use quality you already have more or less infinite space and energy, putting down 20 assemblers that consume less energy than an EM plant really is not that much of a hurdle, at that point you may as well spawn infinite legendaries using the editor.

The description boasts that it has a "whopping 750% power cost" with enough modules.

Which is like ok, so instead of the assembler eating up 400kw, it will eat up 4mw. My god, however will my power grid be capable of handling such a burden? That's like 2 entire steam boilers. I'm only saying this because I'm looking for a proper deterministic quality mod, but so many of them seem to think that forcing you to construct an extra boiler is the be all end all of penalties.

At the level where most people use quality you already have more or less infinite space and energy, putting down 20 assemblers that consume less energy than an EM plant really is not that much of a hurdle, at that point you may as well spawn infinite legendaries using the editor.

In that context, what kind of downside, within that which modules are even capable of imposing, would consitute a meaningful downside?

Also, you mention wanting "true deterministic quality", but mods cannot do that, at least not without completely sidestepping the entire quality-generation mechanic in vanilla; there is no way to change how quality computations are run during crafting from within mod code.

A meaningful downside is a resource cost equivallent to what it would cost to get the item in the first place. Like every 100 crafts a rankup is guarenteed with 1% quality.

Energy and pollution will never be a real downside because both are meaningless by the time you get your hands on quality.

A meaningful downside is a resource cost equivallent to what it would cost to get the item in the first place. Like every 100 crafts a rankup is guarenteed with 1% quality.

This is not something modules can do, at least not in-engine. The closest I could think of implementing such a thing would be for a mod to monitor all craft events (EDIT: I just checked the API docs and there does not even seem to be an event for this, so this entire idea is probably impossible), check the modules in the crafting machine, and increment a counter, keeping track of each one independently, and then modifying the output of the machine as necessary. However, not only would that be an ugly hack, and a horrendously unperformant one at that, it would not even reliably work because the item could just as easily have been removed and put onto a belt or something (at which point it cannot be distinguished from any other instance of that item, bearing no marker of where it just came from) and so there would be no item to bump the quality of.

There is actually a similar mod that has these problems making captured spawners give matching-quality eggs; it too has a ton of edge cases where it fails to properly increment the quality, not to mention performance overhead, and for the same reason. And that mod only has to track captured spawners, not all crafters.

A larger departure from your idea, as well as the way quality is experienced (and completely forsaking modules entirely), is to just add new, more expensive recipes that output one tier higher quality than the input. But that is so far removed from vanilla in feel that it has its own problems.