I know that when sharing fe, any records, temporary or not are exposed to all users, so I don't see why a public variable would not be. Obviously you don't want to hear about how this db is going to corrupt at some point because it's not split, so the banality of this is that whatever "fix" you employ, it won't last. At some point the db WILL corrupt and no telling when or what will be affected.
IMHO, you need to push back. Read up on split vs not split dbs and grab all the info you can find and present it to your boss, who then needs to rag on the IT gods (or their boss) and make it happen. The alternative is to pay you to develop and maintain something that is doomed to fail at some point. You might want to keep the email where you present your findings so that you can refer back to it if they say you did a crappy job.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.