How to use "Opt Block" and "Opt Stop" in QtDragon

Can someone point me to the documentation on how to setup/use "Opt Block" and "Opt Stop" in QtDragon?

I tried putting a slash at the beginning of a block of code, and all the combinations of Opt Block on/off and Opt Stop on/off before clicking "Cycle Stop," but I couldn't see any change in behavior.

Also, I noticed that I can't turn them on or off while in Auto Mode, but that seems like it should be the mode I would want to do that in. ??

I searched for "Opt Block" and "Opt Stop" on the following two pages:
linuxcnc.org/docs/html/gui/qtdragon.html 
linuxcnc.org/docs/html/gui/qtvcp.html
and generally in google, but couldn't find any love.

Are there .hal pins?

This is not a priority, but I'm curious.

Thanks!

I just added:
/(PREVIEW,hide)
to a program and to see the difference in the graphics view (after each toggle) I had to reload the screen. Maybe that should be automatic?

I'm pretty sure you don;t need to reload for actual Gcode commands, but the options must be set before running.

Ah! Looks like the "Reload" button on the panel with the Opt Block button is indeed the trick.

For clarity in case someone finds this, Opt Block ON, with green light, actually seems to turn "off" whatever follows the "/"

Thanks!

What then, does "Opt Stop" do?

M1 will pause a program if optional stop is on.

Oh! OMG.

Now I know what those buttons do. I thought they were supposed to be activated by the slashes, and now I've just learned about those M0, M1 codes.

[Dang, I have so much to learn ]

Thank you!