well not sure why you don't trust boa. Its braided steel cable, probably a tensile strength of around 300lbs. You wont be putting that much stress on them.
Don't think you will get used to the squish. You wont. And if you managed too, well the risk wasn't worth it and I'd still bite your head off. If you have too much side to side room, look at salomons, they tend to fit narrower. And Vans seem to have smaller toeboxes if thats where you have too much play.
That thing I do to escape the world and have fun with my friend