It's not 10 minutes AND up to 4 trades, like you claim. It's a 10 minute timer OR up to 4 trades, whichever is earlier. The worst this system is doing is making you come back to refresh your trade before your 10 minutes is up if you happen to have sold all 4 free lots. On that note, if you did have thousands for sale, what you'd want to do is sell 1/4th of that quantity and offer 4 lots. There is no 'stack' limit on the new trade system and will be limited only by what your storage limit is. There's a lot of interesting stuff going on with how they've side stepped the current three way handshake for trades and it'd be worth your while to look at it in more detail.
Eitherway, this is something on the test server and people have been offering feedback here:
http://forum.tsotesting.com/threads/...trading-system