Are you willing to try tiddlystow version 2 (this is what @Mark_S is referring to as “new TiddlyStow”)?
It currently has the limitation that your single file wikis have to be stored the same directory as each other. In most other ways, it is better than tiddlystow version 1 (my favorite feature is that each wiki has its own bookmark-able url).
See Tiddlystow version 2. Now supports more browsers for more details and screenshots.