I understand you want to know the information for your purchase decision, but from the manufacturer's side, they are not mandated to release such information. The analogy to food from the supermarket is a little bit misaligned, because ingredients of the food may pose health issues and seller is required to attach such information on every product. In that regard, all these tech devices must be sold with detailed information on potential health risk, like radiation etc. The type of chip, op amp, circuitry, etc on the other hand, are essentially all protected information, they are not required to release. It's up to them. Such information is analogous to 'recipie to grow the crop' or 'recipe to cook the deli food', if you want to use some analogy, and of course, supermarket or food industry is not mandated to release such recipes. They can say "AAA grade food" or "This is favorite of chefs in Michelin three star restaurants", even it is used only once by the chef. So called marketing hype.

In any case, users can get information on the chip/opamp if they are willing to open the box, but at the cost of losing warranty. At the price point of UCX or UFX, I don't think anybody is willing to do that (if it's B**ringer stuff, I'm glad to crack open....), so the informaiton from the user side is really scarce.

If you need the chip number of ADC or DAC, look up Ross Martin audio, and they make ADC/DAC units with these information fully disclosed.

In the end, the ultimate decision needs to be made by listening the unit and comparing to your FF400, in terms of sonic quality. At that point, if you hear the difference (in a good way), the chip ID really doesn't matter. If you can't hear the difference, then return policy is more important. At least for me, when I first listened to UFX, the difference from my previous converters (M-brand) was dramatically big, so I don't care somebody says UFX may be using the same chip or not.

Hopefully it makes sense, and sorry for the long post.