This is not a high priority for us, but it is sometimes useful to place the unnumbered table of contents at a position other than the top. As it works now, that does not seem to be possible.
If TOC is given one argument can multiple occurrences of TOC be present in the same article? Your statement above and the wiki codes article do not make this clear, in my opinion. A short sentence on the effect of multiple occurrences would settle the issue.