ECHO.%DATE% %TIME%: Line 1
ECHO.%DATE% %TIME%: Line 2
results in only the first line being executed
This is the case either via the admin console (which certainly gives the impression that we can enter multi-line commands) or programmatically using the ISchedulerTask interface.
I'll bring these up with Dev. It took some work to get things like this working in v1, and it appears we've broken it in v2.
In the meantime, if you go the Admin Console you can do:
ECHO.%DATE% %TIME% && ECHO.%DATE% %TIME%
And that should work.