Thanks millercarbon. I'm familiar with what you are talking about, having experimented with the other spring footers. I know the Townshend are stiffer, but the Thiels were stable enough even sitting directly atop those springs.
The Joseph speakers are an entirely different issue though. I would not trust them normally without the outriggers, as they could easily be tipped over. Unless there is something in the speaker bars that secures them, it seems very dicey to add even a bit more tippy quality, without the outriggers to help.