I assume there's classification going on where a really basic "Hi how are you?" style request sent to a high-effort instance can be routed to a lower-level instance. This... is pretty much fine with me, assuming they do a good job of it.

I would also assume they use nebulous labels like "Medium Effort" or "High Effort" map to quantitative amounts of compute allocation... and that these amounts can be varied manually or automatically. Right?

I mean, there's a reason why they call it "High Effort" and not "Exactly 5 Minutes of GPU Time on Exactly 10 GPUs." They want to be able to move those sliders and tweak those knobs.