I would put master power switch, e-stop and pause with outer controls buttons as related under the common “direct physical controls”.
Why because design a pause system does involve taking in account not to cause issues if someone fits an e-stop or master power switch.
It is normally better to design direct physical control placement and the like with a unified overview. Unified layout would be useful in cases people go to assist with friends machine.
Even with a pause system you might want to have a relay to cut power off from motors like the bare min Category 0 e-stop. So I see possibility for some electronic overlap between the pause you want and e-stops.
This is the super fun part about the different terms. Just because you call a button pause on a machine does not forbid it performing an action of an e-stop advantage calling it pause you don’t have the same level of legal requirements. Pause button on a remote is heck lot simpler due to not having regulation.
E-stop and pause don’t have to be electronically completely different things. With pause it does pay to consider if like the power to motors and the like should be cut by relay to increase safety if person is moving around machine while pause is set. This again is Must be design with operator in mind. I high lighted that term out of OHS so much for lot of reasons because it is what caused the electronic side of e-stop and pause buttons to overlap. If machine will hold itself in position without power leaving power on everywhere with pause hit is bad design. Same applies to implementing just a simple stop button.
There are a lot of cases were people make the mistake of not powering stuff down with a relay in case of pause. Implementing pause correctly could truly involve putting everything in place that you could just wire a Category 0 e-stop button into the right place and it right also have created a system that support Category 1 or 2 e-stops without major trouble even that I prefer them not used.
So splitting this into two separate items could make life harder.