First off, Thank You for all your hard work and effort. Love almost all your work. I thought it was great when you started to take the time to add metadata so it'd show up in Smart Content, and now DIMs. Are you using the Content Package Assistant from DAZ, some other DIM creation app, or making them 
manually? I got Content Package Assistant so I could convert non-DIM content to load in DIM.
I have noticed that along with your DIM files downloads, you have .dsx files. Are these the ones that show up in the Downloads folder after you start DAZ Install Manager? if so they are unnecessary. Install Manager creates these files from the .zip files automatically. I believe that they get overwritten when Install Manager scans the zip file. Not sure though.
Also, if you are using the Package Assistant or even if your not. You don't have to have it start with IM. When I convert non-DIM files I'll use RE for Rederotica, RO for Renderosity, depending where i get the content from. DIM will read it as long as the naming format is right and it's a .zip file. For example I'll use the name of one of your recent updates, (which I'll be changing for my own organization anyway.).
IM80056902-01_StereoLoveforGenesis3Femalev4.zip I'll change to RE00056902-01_StereoLoveforGenesis3Femalev4.zip. I do this for my own organization within DIM, and I do it through Package Assistant so I know it load. I don't change any files or locations inside the zip file. Just basically change the name, though I think Package Assistant does rewrite the Manifest and Supplement files to reflect the new name.
Anyway THANK YOU for all your hard work and efforts to make your work easy and painless to load into our Libraries.