You might try creating a Someday/Maybe folder in OF and setting the status of the folder to "Dropped". Folders don't have an "On Hold" status, but a "Dropped" folder behaves like an "On Hold" one would in every sense. The contained items don't show up as available, but aren't archived by the auto-archive command. I use a Dropped folder to store template projects and it works well.
I created a Someday/Maybe folder and set its status to dropped as you suggested. The problem is it immediately disappeared from view. Naturally I had to adjust the project filter to see it again, but it didn't show up in ANY of the available filters except "All Projects". I assume as time goes on that view will become quite a large and cluttered list of completed, held, and active projects making it difficult to find the Someday/Maybe folder. This also makes it very cumbersome to add projects to the Someday/Maybe list which I'm expecting to be a frequent occurrence.
Or am I missing something here?