[TxMt] Tab stops work strangely with nested snippets?

I want to produce [origin [pt x]]; using a snippet called msg (short for message) that looks like this [${1:Receiver} ${2:message}]

When I write msg and hit tab I am presented with [Receiver message] where Receiver is highlighted. I write origin and hit tab. Now I get [origin message] and message is highlighted.

I write msg again and hit tab.

To my surprise I get [origin msg] with tha caret after the last bracket.

So it seems that TM is giving priority to the outer snippet??? But I think that two other alternatives might be better

Alternative 1: Forget all tab stops for the first snippet when an inner snippet is activated.

Another alternative is

Alternative 2: When hitting tab give priority to the inner snippet first and when it is finished then give focus to the outer snippet and let it do its thing.

If I am wrong in my thinking tell me why. If I am right maybe it is some programming difficulty with nested snippets that prevents the desired behavior.

Thanks Bob