How to configure a soft stop button - Not E-stop

I have been trying to come up with a soft stop for a while now and the solution is not coming to me. Looking for ideas.
I have UC300eth-UB1, UCCNC, DMM Dyn4 servos.
I have wired the UB1 with a push-pull estop, charge pump, safety relay, and a contactor. The safety circuit works well and as expected.
I have two momentary switches (on & stop). I use the on to set the safety relay and energize the contactor. Currently, I have the momentary stop wired in the e-stop circuit, so I can stop with out using the estop button.(even though it still performs the same function as killing the power)
I want to use the enable inputs of the drives as well as the (WJ200 VFD) to create a soft stop, instead of killing the drives power every time I want to shutdown. I feel it would be better to have a controlled shutdown, but I am not coming up with a good solution. I could swap the momentary with a latching switch and wire to the UB1 inputs, but how do I connect the switched input with the needed output to open the drives enable circuit? Any input?

You can add a stop function of the UCCNC in the input triggers.
That attaches the stop function call to an input pin state.
The stop function makes controlled stop.