I decided to buy this metal sifter plate as it wasn't much more than the cost + shipping of a similar product made with much less durable materials. Seems well-designed and arrived thoughtfully packaged; no sharp edges, missing parts or any other quality issues. Safe to say this sifter plate will serve me for years to come!
The sifter plate fits perfectly in my store-branded 5 gallon buckets, with no gaps around the edges even if I put it in a bit crooked, and the U-bolts make it very easy to remove. The few pupae that fall through the grate are either small or freshly molted. I don't mind hand-picking these pupae, but if your goal is to breed bigger worms, leaving the small pupae behind probably helps with that goal. The sifter tends to catch any beetles in the batch too, which is helpful.
I appreciate Mealworm Farming Solution's care and attention to detail, and look forward to seeing what they come up with in the future. (Additional plates for sorting worms by size maybe? Fingers crossed!)