A patch I've been using for a few days now, thought maybe
someone else will find it useful as well.

Without the patch, Ctrl+F (or Insert) triggers file name
completion, but when you have more than 32 matching items,
it just prints "[XX files]" and gives up. This patch adds
to the behavior: rio provides more and more matching items
if you continue pressing Ctrl+F, despite the initial
message. It stops when the current completion does not
give results anymore, so as not to spam with duplicates
if your key repeat rate is as high as mine.