The crash is from recursion. echo iteration of the loop is calling the same alias which again loops - over and over ....... You should use !away from within the loop for cases like so.
This is easier and quicker though.
- alias gaway { scon -at1 away $1- }
/gaway "away msg" sets you
away on all
connected CIDs
/gaway on its own sets you
back on all
connected CIDs