I heard that the festival I went to the other day in Hokkaido is held for twenty days.
I was wondering if Hokkaido should be spelled 北っかいどう?
But now in the middle of writing this I think I’ve changed my mind. First of all, there’s probably no actual spelling convention here; I imagine native learners rarely, if ever, see `partially kanjified’ words like this.
Furthermore, I think the idea WK has here is for you to recognize the sokuon on your own and see 北かいどう.
Doesn’t seem worth pinging contact, but I thought it was interesting enough to post here.