Suppressing TextSpanner right boundary text at a system break

[James Harkins]

Apologies if this is a basic question. I've searched but I didn't find the 
answer.

I have many text spanners with text for both the left and right bounds.

If a spanner crosses a system break, I would like the right-hand text to be 
hidden at the end of the first system.

The spanner represents an instruction for computer ensemble performance: at the 
left bound, begin transitioning to the next state; at the right bound, you 
should have arrived but not before.

Currently I'm getting "arrive" printed to the right of the last bar line of the 
system break. The performers should not arrive at this point! The score is 
misleading if it suggests that performers should have arrived at the end of the 
system.

I searched the manual and didn't find it. An LSR search for "spanner" finds a 
technique that is supposed to hide the spanner /line/ after a break (not what I 
want). I haven't found anything about controlling boundary text visibility.

Thanks,
hjh