Yes that's what I did, IS instructions worked fine. It looks like Mansion themselves put up offers on the sides they want, like when you see 100k available.
I notice a feature to withdraw your offer which is a nice option. Funds stay in account after offer is made, I'm guessing until they get a match.
Is it OK to have offers out that exceed your balance ? It seems to be, I would think. For example if you had $1,000 in acct can you put out offers of $500 on 5 different games. I'm guessing if 2 find matches then the other 3 just go away for lack of funds .
I think it will catch on big in time, hopefully remaining fee-free. They must be eating some fees like NT fees for exchange only players.