For me it doesn't make much sense to have an import function for a monophnic 16 step sequencer.
Writing the code to handle all the exceptions (multiple tracks, polyphonic pattern, unquantized notes, patterns with more than 16 steps, glides etc.) will be more effort than coding the main import function for importing a monophonic 16 step pattern.
I think it shouldn't be too difficult to enter 16 notes into the sequencer, right?