[MrFlippant]

Re: File Size, even an STL can be pretty large when the model is highly detailed. One way to reduce the file size is by reducing the detail. Sometimes you can get away with a pretty significant detail reduction without impacting print quality.

Fusion 360 has some mesh reduction tools, as does the forthcoming PrusaSlicer (currently in Alpha). Meshmixer does as well, I believe. 

Also, 3mf is a compressed (sort of) file type, so if you can download the mesh into a program (such as PrusaSlicer) that can export/save as 3mf, then the file size will be a lot smaller in most cases, without any loss of detail.