My company has many parts and assemblies created with older versions of Solidworks (primarily '16 and '15). We're not using PDM.

We're currently using SW2018 and would like to use these older version parts and sub-assemblies in new assemblies. They are also used in older version assemblies so we have no desire to convert them to the latest version and can see no business value from doing this. Sometimes these new assemblies are just for a quick-and-dirty visualization that we'll probably use only once, but would like to save just in case. Ideally we'd keep inserted parts as older version files, and we'd just pay the conversion hit with a few extra CPU cycles any time we open an assembly that uses an older version file (so an older file gets converted in memory on-the-fly as the assembly opens, but the data on disk is unchanged).

There's no issue when you insert a older-version part into a new assembly, but we hit a snag when we then try to save that assembly. The save dialog shows "The following models referenced in this document have been modified. They will be saved when the document is saved."

Ok, so maybe we can manually uncheck the part files we don't want to save in the prompt so we can at least save the assembly. Nope. It's all or nothing.

Maybe we can make the part files read-only? Nope, Solidworks still demands they be saved as new-version files in order to save the assembly.

What if we make the inserted files read-only and enable the check-box System Options >> External References >> Don't prompt to save read-only referenced documents (discard changes). Hey, this works! So Solidworks has the capabilities to do what we want. But we've got to touch our original files and change the access permissions, which can be a lot of manual work. Plus if they're not already read-only its because we don't want them to be...

I think what I really want is a check-box that says "Don't prompt to save referenced documents created with older versions of Solidworks (discard changes)." Are there any work-around that could approach this?

One possibility I've found is if I check "Enable multi-user environment" under System >> Collaboration, and also check the "Add shortcut menu items for multi-user environment", then I get a RMB option to make the in-memory copy of the file Read-only, which will allow me to Save the top-level assembly without touching the part file or its access permissions. But this again seems like a lot of manual work for a pretty routine situation that seems bound to occur when you have content generated across multiple years of product development.

Any ideas?