Yes.  

It's documented - admittedly somewhere buried in this thread.

Since the generator has a so called loop mode (which made it faster by eliminating startup-times), LBC cannot stop it during a round as it evaluates keyboard input buffer after a round - also to spare CPU cycles.
I'm thinking about a way better mechanism that would allow for a) immediate ending and b) not losing work done so far, but that needs more work and there are other pressing things.

So until then, pressing "e" means your LBC client will end gracefully in 100-200% of the time X you gave with -t X (depending on when you press the key).


Rico