I've done a few material conversion scripts in the past, I can give it a shot in my free time.
What I need from you:
The sketchup file with materials/textures.
The 3dsmax file - how it appears directly after you import the model.
I tried with one from the 3dwarehouse however I work with 3dsmax 2021 and it only accepts sketchup v8 export. These also import into 3dsmax as standard (legacy) materials instead of physical, so I need to know why this is the case for you (to clarify - why are they importing as Physical Materials instead of Legacy). If Sketchup imports as legacy by default this is important to know.
Also give me a detailed material so I can cover all situations if possible, diffuse/roughness/normal/opacity etc or whatever it is that's "standard" workflow for you. The model doesn't have to be complicated, a box will do. Or if you have a few different material setups then a few boxes will suffice.
Last thing is since I work in 3dsmax 2021 so not sure about forward compatibility but ill see what's possible.
Also devs reading this, has much changed in the Physical Corona material since Corona 7.0? We are still using this version due to our current pipeline.