I would pinch them out just below the fourth truss.
That is, leave a bit of growth above the third truss.

Keep your hands of my truss, young lady!
On second thoughts . . .

I noticed rather late that two of my plants had bifurcated, and ISTR
that it is best to keep only the main stem for flowering.
Anyway, I cut one of 'em off, as it looked like one of those
"in-between" shoots which are supposed to be pinched out as soon as they
appear.
The Alicante was the most obviously bifurcated.



Not sure that bifurcating and handling other peoples trusses is quite on
topic for urg but I did find the information concerning the pinching
most useful.
Have you ever had any trouble with your Euphorbia Fireglow?

Bobbie;-)