Simple relay control

Hi, I was just handed a new OpenGrab and asked to try it out.

First test:
Just to use the PCB mounted push button…
Am I correct to assume that I can apply 5V to the power pins of the PWM interface
then just use the button (SW1) mounted on the PCB to test?

Second test:
I need to remotely control this, but don’t have time for RS485 or CAN or PWM. I’m assuming
I can just use a relay… I can connect my relay contacts in parallel with SW1, but I also see
there is a pushbutton switch that plugs into P4. Can I use those contacts as well?

This should help:

Paging @NicaDrone for further assistance.

I bet he has Rev R5D

Yes, I see on this version of the schematic, there is J9 instead of P4&P5, so it appears that this is the correct schematic for the board I have.