If you want max-like smoothing groups you will have to create new materials each with their own smoothness values, much like you would for smoothing groups in max, ie. select polygons, apply new smoothing group (in this case it is a material in modo) then play with the smooth value to get what you want.
I would start with as few materials as possible and just mess with the smoothness angles for each. If you want really rigid sharp corners, then adjust it really low. If you find that this isn’t enough then break the materials down into smaller groups of polygons with their own smooth values.
Material smoothness vs max smooth groups are almost identical in the results you can get. They are just implemented differently. One you edit at the geometry level, the other you edit at the materials level.
Also, it shouldn’t matter how many materials you have to use to break up the smoothing, so long as they all reference the same bitmap image, assuming you are using textures.
This is how our artists here at DE put objects into our game engine using LW.