Can't comment on wearing the hiking boots, but do know that you need to up a size on your footwear for stocking foot waders. For ex. I normally wear 10 1/2, bought wading shoes in 11 as the don't make them in 1/2 sizes for me to get 11 1/2, 11's ended up being to tight. Got a pair of 12's and they are comfortable and light even when wet.
Your wading boots for the most part are made not to retain a lot of water and there for don't weight you down and dry quickly to prevent mildew/mold.
So, I just had to have a look at the possibility of doing this. The first thing I noticed was when compared wading boots are much more generously cut ( roomy) I stuck my hand into a couple pairs of hiking boots I have and did the same with the two pair of wading boots. The wading boots have a ton more room.I don't know if it'd be worth it with the size (s) bigger you'd have to go with the hiking boots. Let us know how things go with it.
pullin strings, flingin flies and scraping stones...