Adding more file option to one big archive would indeed make sense.
Separate files mean separate downloads unfortunately.
I usually upload one Zip archive containing everything, and ad information about its content in the descriptions. This indeed makes the model escapes the filter option, however if you set it to other then it will appear always.
You can see the file options as a tagging system (3ds max ,fbx or obj etc.) the option "other" is no tag at all, so you can't filter it out.(models will always displays whatever filter/tag is used).