The cap should be a microcap,
Minicaps also exist with 1.1 bar rating and if you force it on a microcap neck, the effective control pressure of the cap becomes more than 3 bars. (45 psi)
The pressure rating is just one part of equation. If someone uses the literal wrong design its their problem.
Btw, radiator fan not working will severely overheat the engine and can blow the plastic top of an old radiator as the discharge rate of the cap’s overflow is not built to handle those kind of flow rates.
Meaning
You can blow the radiator top tank even with an original radiator cap if your fan doesnt work and the engine overheats badly and if the radiator is pretty old (heat cycled)
