The new growth on this spruce is about 1 and 1/4" long at this point, I would imagine now is the appropriate time to pinch about half of that new growth off? As you can see the new growth is beginning to fan out and mature into a typical branch.

Why would you pinch this off? I wouldnprobably let the branch grow and cut back at a later stage. Plants neef hrowth for health.

Everything I've read about spruces says to pinch off the new growth by about half.
Allegedly it encourages fuller growth as well as back budding.

The idea isnt to prevent it from growing, apparently even once you pluck half of it off it will still mature into a full branch.

WesternGrower wrote:

Everything I've read about spruces says to pinch off the new growth by about half.
Allegedly it encourages fuller growth as well as back budding.

But you have no growth there.. You have just broken buds and no branch growth.
As said. I would let it extend to you have maybe 5 cm of growth. Then cut back (For mature, well developed specimens). And if this is a young plant that needs to first develop trunk or branches, I would not cut back at all.

Cannot tell where your plant is at.

The growth in question is coming off the end of the branches
Here is the whole tree, under a bright light because its dark out.