I've used polarity reversal converters on daisy chains and they've worked fine?
If you need to mix and match anything that needs full isolation, you can still use the two independent outputs to do that if you need to.
The thing that I've wondered about some of these new cheaper power supplies is how the total MA draw claims printed on the units can sometimes be higher than the MA supplied by their bundled power supply adapters, but I suppose if the 9v sections aren't isolated that kind of explains it on some level.
I've been doing some deep digging and it really is difficult to find any supplies that DEFINITELY have individually isolated 9v outputs at this price point. Plus, it seems that there are really only a few specific models that are being rebadged to infinity by these cheaper companies. I know the fancier ones with the steel shells are mostly Palmer units, but the slimmer ones like the Asmuse one you got seem to be ten-a-penny, and I would be genuinely shocked if any of them had individually isolated 9v outs. I'm fairly sure I remember seeing both the familiar Palmer DC8 and another one in the same case that advertised the fact it had individual 9v isolation, but that was a few years back now and I can't find it anywhere. It was called the ISO8, and I know a company called Vitoos used to make and sell one on eBay, but looking now it seems to be gone. Even so, without ever having had one in my hands and tested it for myself, it's impossible to verify any claims of individual isolated outs because there's so much bullshit talked about this stuff... Cheapest I saw it in 2018 was somewhere around £40, so if that specific model is still floating around under a different badge, it's definitely more expensive than that now.
As an aside, Vitoos seems to still be around, turning out the same folded steel enclosure units, but now painted either white or yellow depending on their function.
http://www.aliexpress.com/premium/vito ... ext=vitoos
They look the part, at least, but even a quick scan suggests that none of them have individual 9v outs like you're looking for. And that's without mentioning the fact that even for a relatively unknown brand like Vitoos, these power supplies are still £50 at a minimum.
