I tried and I got some good things and some bad ones: the epubcheck seems to have problem with void; touching the <a> elements do not turn the page; but the events associated to the span element inside the <a> are not activated. I have also a problem with text colors, it seems Kobo do not follow my css a[href] asking for black color.
I also tried it in <a> inside a svg, but it seems it is not working.