Without manufacturers posting their lab tested specs on ripple/noise floor at full load, it’s hard to know sometimes. I understand the reluctance, since some modules are the culprits, injecting noise back into the EuroRack rails.
As of about 1.5 years ago (there are some new options now), we tested just about everything available for EuroRack. Most of the switching topology supplies perform horribly with analog video systems.
There’s a list of recommended power supply options here which includes everything that we found acceptable to get what we’d deem as acceptable performance from our modules:
Out of respect for other manufacturers, and that we wanted to make sure to give room for revisions and improvement, we don’t have a “bad egg list.” (But we did test everything mentioned in this thread.) We strongly recommend if you want the modules to function as they are supposed to, to limit your power supply configurations to those on the above list. Clean power and performance are much more important than the perfect skiff case or most budget friendly option.
The practical concern is switching noise bleed. This will show up as diagonal scrolling jaggies on the edges of any high gain process or hard keyer, but be present in everything. If you see a clean image with no diagonal scrolling jaggies that looks good to your eyes, then I wouldn’t be too worried.
If you are seeing something like that, you may be very surprised at how much better your modular will look if you replace the power supply.