When using a <limit> in mutt's message index, I always try to hit 'q' to get back to the index view, but of course there's nothing to quit. The macro below changes 'l' such that 'q' will unlimit, and a subsequent 'q' will then quit mutt:
macro index l '<enter-command>macro index q "<limit\>.<enter\><enter-command\>bind index q quit<enter\>"<enter><limit>' 'limit with quit enabled'
(The weird > quotes trick the parser into not parsing <fct> in the outer <enter-command> layer.)