SVG in TOC (EPUB3)

I tried Ace by DAISY (gui) 1.3.2 on an EPUB3 book, that contains some SVG content documents.

The reading order in the OPF: spine, the NCX:toc and the XHTML:toc is the same, but Ace reportes as 'serious':
TOC must match the publication reading order (Frontispiz.svg [id!?])
Ensures the publication TOC is ordered (Frontispiz.svg [id!?])
Order the Table Of Contents items (Frontispiz.svg [id!?])

Is this a bug or intention? Or did I miss something?
epubcheck 5.1 thinks, this is ok, no warnings or errors here.
Another order will result in an error message of epubcheck.

I know, that some presentation programs have bugs concerning SVG content documents, but this is an accessibility issue of these programs, not of the EPUB3 book.