Dedicated 4-way cabinets are normally done vertically, as the vast majority of 4-way games are vertical in nature. Punchout isnt a vertical game, neither is Omega Race, nor is Bank Panic. Omega Race also doesn't use a joystick.Punchout's dual screen nature makes supporting it a nightmare anyway, regardless of machine.
Dambusters is an odd case. By everything that is holy it SHOULD be an 8-way game, but it isn't. It does however handle 8-way input rather well for a four way game, always defaulting to the new direction when it encounters a diagonal.
I am not sure it is worth installing a 3rd button is worth it just for bad Scramble clone and Bank Panic.