At OpenOctaveProject, running Ls from the terminal is more or less default behaviour. Once a frontend like fantasia has been used to build our large orchestral templates, then the cat command is run from inside a script, which starts not only LS, but jack, and oomidi as well.
Good to see someone else getting good CPU and RAM resource value out of LS's backend/frontend design, and not afraid to use a terminal as well.
Yes, adding a sleep value is good, and if you decide to run another app from your script after the cat command has been issued, you should add some sleep there too, to the equivalent of how long it takes to load your .lscp template. (plus a second or 2)
Alex.