JP15 – position to split coils to use either a neck or bridge single coil pickup?

I know that if I am in position 2 and I pull up on the mag tone I can use both a single neck pick up and single bridge pick up in parallel. I’ve tried putting the guitar in position 3 or 1 and then pulling up the mag tone, but it doesn’t seem to be different than just putting the guitar in position 3 or 1 and not pulling up the mag tone. It is possible that I’m not hearing the difference. But the instructions on the JP15 control diagram (01-01-2016) does not show explicitly how to use only one single pickup so I’d like to make sure I’m doing it correctly.