I watched the first page on Q5, and it looks good on a smartphone, as far as I can tell?! The radio button move below the item text, which fills the whole width of the page.
> One more major issue I notice right now, is that on mobile, the "lead text for items" repeats itself
Yes, that is intended, because you won't know the text from the page's top, when you scrolled it out of view for 10 pages.
If you think that the text should not be repeated, you may understand it as some kind of "instruction" instead of a "lead text for items", maybe?