TIR navigation depends on using relative URIs for local pages so that browsers can follow links regardless of whether the pages are hosted on a web server or on the local file system.
However, the path Net Front (and likely most other browsers) uses to resolve a relative URI for a given directory may vary if the directory can be accessed both by it's natural path and by alternative paths created with links, which TIR uses to create thematic connections between directories.
This renders relative URIs void when a page is accessed through a link.
Number 4. looks like the most efficient way to preserve intended functionality.