At the start of my drawing process I often use JPG “Matched” photos in my models, and I normally use imported components for the occasional common component (that I don’t see the point in putting in a library) towards the end of my drawing process.
This means that every time I start a project I have to navigate away from the directory structure that I store components in to the location of the photo. Then navigate away from the photos back to the SKP directory when I’m looking for bits to add.
I would like the directory remembered from the last time I imported a file of that type rather than just the last time I imported anything.
I believe the operating system’s file have it baked in to remember its location. Because of that there is one file path location for the whole dialog, independent of options like file format. SketchUp doesn’t currently implement/override anything to achieve this behavior.
The feature you suggest sounds very sensible to me and could increase productivity. Some web browsers (apparently only Firefox) remember download paths per domain, so you can save literature from one website in a different folder than exercises from another domain, without having to navigate each time through the folder hierarchy.
This functionality is built-into Windows, but a program can override this.
On the Windows edition of SketchUp, you can set default paths via Window > Preferences > Files
For components, the “Components” path is used when you "open a local collection.
For matched photos, I don’t know what is used.
On later versions of Windows the key where the paths are saved is:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\ComDlg32\OpenSavePidlMRU
Each file extension has a subkey, with multiple previous paths saved.
They used to be plain text and easily readable, but since at least Win7 they are binarydata.