Well, a miracle happened, and the TZ-4228B arrived yesterday!
Overall, it makes a decent impression. The DuPont jaw is 7mm thick (same as on SN-28B), the other three jaws are 4.5mm thick, in both cases evenly split between wire and insulation dies. The DuPont jaw works, neither mangling nor under-crimping any of the contacts I have. The smaller female contacts end up with the insulation crimp ever so slightly too wide, such that inserting into a housing has a little bit of friction, but it does work. I’ll have to try it with some thinner wire. The gold plated ones, which are a millimeter longer and clearly designed for thicker wire, work beautifully with the 24ga (0.22m2) wire I was testing with. (However, if it were me, I’d have made the wire die only the 2.25mm thick like the other three. I don’t know why they kept it 3.5mm thick, since no DuPont contacts need such a thick wire jaw, and a thinner one would make positioning the cheap smaller female contacts a bit quicker.)
Jaw #2 (going by the numbering on the image in the original post) works perfectly for both variants of Molex KK clones that I have.
I found some JST PH (2.0mm pitch) connectors at work yesterday. Jaw #1 is supposed to be for those. I’ll try it out and get back to you.
In summary: the AMP Ampmodu Mod IV crimper ultimately produces slightly nicer looking crimps, and is definitely superior for very thin wire (since it has jaws specifically for them), and it’s definitely easier to use thanks to the insulation stop it has. But it’s definitely not as flexible on contact compatibility. The insulation stop consumes space that the cheap smaller female DuPont contacts do not have to spare, making it difficult to not crush those without careful positioning. The TZ-4228B does a good job on every small contact I threw at it. Will it meet coppercone2’s standards (or, indeed, military or aerospace standards)? No. But I think we may have a winner for hobby use. At the price, I don’t think it can be beat.
I still have to try it with some D-sub contacts, too.
I’ll also mention that I was able to adjust the dies on the TZ-4228B slightly, so that the anvils align ever so slightly better than how they shipped, and this improved the crimps a tiny bit.