Box noises, when is BR / Closed worse than OB? + upwards Cardioid speaker ideas

[OllBoll]

Hello all!

I'm wondering in what frequency range that the so called box noises in Closed and Bass Reflex appear, is it a limited range or is it on the whole range?

And I saw this article by Linkwitz on Cardioid OB mounting, are these also exempt from box noises as other Open Baffles?

What I want to build is an upwards mounted speaker with ideally no box noises to radiate an omnidirectional pattern around it, I had an idea some days ago with an ordinary upwards mounted OB, but I realize that even if I could solve backwards-wave problems it would still be nulled at horizontal level which isn't acceptable in my case.

Then I saw Cardioid OBs, which if I've understood correctly if mounted in an upwards aligned OB wouldn't have the backwards wave problem at all, and would even spread sound in a better pattern for an upwards mounted speaker.

Which is why I come back to the question of box noises, this Cardioid would driver from about 150 hz and upwards, would it even work? And if it did, would there be any benefit of an Cardioid OB over a BR enclosure?

And also, do you think that an upwards mounted Cardioid speaker would work or would it too have significant limitations?

Thanks!
// The information greedy Olle