A surface mount resistor and capacitor on the back of the board (where there isn't much room) are orders of magnitude too small.
I'm intending to put a blob of solder between pins 3 and 4 to try. I'm experienced with soldering short of replacing SMT components, and I don't even know if a capacitor of sufficient capacitor would be a same size replacement whilst not using such a high resistor value that it would take too long to charge and produce a delay with each step signal.