Pull Up Resistor to Substitute SPDT Function
Yes, your design using a pullup resistor should work fine. It will draw a little more current from the battery when the button is pressed, but it's less than a milliampere and should be negligible.
Sometimes you have to worry about switch contact &quot;bounce&quot; but since your switch data goes through a flip-flop that latches the switch signal, this should not be an issue. Good luck!