We made our bump out of wood too. Our drive train couldn’t make it over wood, but flew over metal. I wouldn’t worry too much although we still had a metal bump to test on. Of course there’s no definitive answer without testing it but I wouldn’t worry too much.
Try painting the wood bump with the same style paint as the metal has. also try a lower gear ratio(1=1).
I have a 4 motor mecanum drive with 1=1, elevated chassis too, but I can get over any bump of similar dimensions, even one created from the vex 5x25 plates and some 1x2x1x25 C bars. I can also almost get over an entire 2x4 - (the 1.75 in side)
also make sure you are using the corect wheel orientation and the correct programming.
Paint may not make much of a difference. The texture of the bump will affect your grip and will matter more that the paint will (I think). I don’t know of a solution other than getting a bump to try it out on, or making an identical one (out of the same material) that is shorter than one used in the actual game.
I would not worry to much about the wood vs. metal if it can clear the wooden bump it will clear the metal one. However that being said if it clears the metal one there is no saying it will clear the wooden one, due to the material.