i run all types of spacers… i have generic 1/4 plates on the rear (drive wheels)
but up front i only use hubcentric… and there are 2 hubcentricities you need to worry about.
hub centric to the lip on the hub and hub centric to the bore on the wheel.
if your wheels will not be 100% centered by your lugs then your wheel needs to be centered by the spacer / hub
i had spacers machined to be centric to the hub and wheel because they were 20mm and therefore longer than the lip on the factory hub.
i am having 32mm spacers made up now and they are also centric to both wheel and hub…
generic plates are not necessarily dangerous, but if you plan to run long term without changing wheels often then you should be getting something proper.