Basically, any professional engineer knows there is some risk with going with that new brand based on some accelerated life cycle testing on a small sample.
A lot of engineering is about lowering the risk and using "best practice". It's like the old "Nobody ever got fired for buying IBM/Fluke/Keysight etc".
In the case of caps, no engineer ever got fired for designing in Panasonic caps if it's within the budget. It's smart design.
If for some reason those Panasonic caps went tits-up because they had a production problem, then no one is going to hound you for the choice of using those Panasonic caps. If you used CapXon, well, good luck defending that choice.
So "best practise" is really about making sure you cover your arse with the same sized pillow as everyone else? Sigh.
Professional design engineering is
all about tradeoff's. In fact it's almost part of the definition of practical engineering.
No engineer has infinite time and money to optimise every single component in the design, and test/characterise/lifecyle test every component in the design.
So what do you usually do for good design practice? Design specs aside, you chose the best quality parts you possibly can based on industry experience and brand reputation, that is possible within your budget.
In fact part of good experienced designer is knowing about brand reputation etc and applying that accordingly.
If you aren't doing that, and are just blindly following datasheets specs as if all manufactures and their parts are all created equal and have potentially equal quality , then I'd say that you aren't a very knowledgeable design engineer.
Indeed, if you sat in a design review meeting for a design where reliability was paramount, and tried to argue that you should use CapXon caps instead of Panasonic, then after being met with snickering and looks of incredulity, you'd get a very stern "prove it".
No that may not be "fair", it may not even be "right", and the no-name caps might perform just as well as the name brand ones, but would you stake your professional reputation on it?
If a no-name cap company wan't to earn their place in "the list" of proven quality cap manufacturers, then it's up to them to do that.
Welcome to the real world.