By "in the heat of the moment", I refer to those times when the keyholder wants the cage off, for instance for some impromptu Tease and Denial or even penetrative sex, but going through the TetherSpout removal procedure I outlined would just kill the mood...
But it is not necessary to remove the spout to have a good time. One just needs to prevent it from retracting too far inside where it could be painful and/or awkward to fish out. For that purpose, there are accessories like the two I own, bought from Tether Products:
The circular barbell (8 Ga. 1" hoop):
Even easier to snap on, the spherical magnet. The one pictured here is 3/8" in diameter. 1/2" and 5/8" spheres are also available. The spout's stainless steel has magnetic permeability, so it will strongly stick to these neodymium nickel-plated magnets.
There are also ring magnets in the same material. I haven't tried those yet, but I have two on order...
Note that the hoop above leaves very little space for fluids to pass through the spout. In particular, that greatly restricts the passage of ejaculate so, for some, an orgasm with the barbell will be ruined, as if someone had pressed the meatus shut with a thumb or palm. Comparatively, the spherical magnets do leave the side holes free of obstruction, so fluid flow is less restricted. On the other hand, keeping the ball on while urinating could be messy!