I know nothing about Sketchup, but this example here looks like "you" simply f**** up the baked vertex normal.

While I do agree about the issue pointed previously (that again can be fixed using the centroid .ini option), what you call 'bad topology' is irrelevant if you handle the baked vertex normals correctly, meaning, don't touch it, don't discard it, don't post modify the topology unless you know what you are doing.

Also it would be more productive if you give a little more info about the DCC/Render engine you are targeting. I did created tons of large rendering (8-20k) using mesh coming from MoI without much issues, at least no more that all the crap you can get with 'traditional' modelling. (usually coming from mistakes not really visible when working in the viewport, but get revealed at rendertime).