The orders are sent immediately. One thing that may be confusing is that the paper broker only processes orders once per bar so you may see a delay. However, with any real broker the order will be handled immediately.
The orders are fed to the system just as if they came from your system (RightEdge actually calls OpenPosition under the covers). I think this is desirable because having different orders routed different ways is a recipe for confusion and disappointment. The only way to tell a discretionary trade apart from a system generated trade is that the description field contains the text "Discretionary". We may opt for something better in the future, but again, I think making decisions in the system based on how the order was placed may be bad form.
There are two new topics in the help regarding discretionary features. They outline how to use them. Did you see those or were you looking for something more (i.e. how do the orders get routed)?
While discretionary trading is a welcome addition, more explanation is needed. Are fill, cancel and update events triggered? Do the trades happen immediately, or at the next bar end (as if they constituted a "trigger")? One concern is that my placeorder procedure sets a number of enviromental conditions that are presumed to be in place when events occur. Is there a flag that distinguishes discretionary trades from others? That might be used to exempt discretionary trades from some checking.
Further, one might want the ability to declare that a trade has occured, one that does not drive events. This arises where you have made a manual trade in TWS and you subsequently want your RE strategy to pick the point to cover.
(I don't find anything in the Help or Guide documentation?)