I can confirm each "solution" here (having tested with 32 and 64 bit variants) and I would like to add something:
Drag and Drop is ALWAYS a two step solution when moving between applications, there's just no way around that even with apps inside the same development ecosystem like Microsoft or Adobe titles. The reason won't surprise you.
Different applications don't talk to each other directly when moving files between them by drag and drop. This functionality is handled by the OS, no matter which OS you are using. On Windows, FileExplorer will take over from App-A (which is sending), and get a link to the file it is using--if a file does not exist yet, you will get the chance to save a file in some apps, others create a temporary file in a space you specify or use the system temp cache--; this link will then be used by App-B (which is receiving).
A compressed archive is only a collection of bits that need to be unscrambled and decompressed into the file(s) the archive contains. When you drag and drop from the 7zip to a FileExplorer window, those files must first be decompressed to a temporary location as they don't yet exist, then they can be moved. This is because 7zip DOES NOT EXTEND the FileExplorer, it is a separate application. However, drag and drop between 2 windows of 7zip will not require this temporary space, it can do it all directly in memory. The same function is found by using the EXTRACT function and giving it a path to dump the files into. However, you should not MOVE or COPY if you wish to avoid temp-caching. Again, these create a temporary working copy, then move that to the path you give them.
You can still select single or multiple items of varying type and size, then Extract them, or drag-and-drop into another 7zip window.