Bruno Le Floch writes:
 > Hello,
 > I'm not sure whether this is the right place to send a bug report on
 > l3tl. 

Hi Bruno

as good a place as any I guess. It probably gives you fast response. 
For functionality suggestions (like the later part of this thread this list is
certainly the right place).

An alternative would be to log a real bug in the ancient LaTeX bug database

under the topic "experimental kernel"

The advantage would be that it would be easier to track if it takes more time
to fix something