Looks like the trunk(?) is constricted just below that section. Is that the graft? If so, may be incompatible.

Adventitious buds / it happens.

Dax

Yes, the scion appears to be overgrowing the stock.

I just found the proliferation curious.
It's nothing to worry about though, right?

-Sam

It might be something to worry about - as jean001a says, it may be graft incompatibility. All the growth increment appears confined to the scion with excess growth there, and apparently little or nothing going to stem (and therefore also presumably not root) growth in the stock. If so, then the roots wil fail in due course from lack of energy supply. Time will tell.

Resin

Just my "opinion":

Often times during grafting, to make a plant fast, a large scion can-be grafted to a smaller seedling. All that is needed is "one side" of the scion to be lined up with "one side" of the seedling, understock... the graft will knit and a larger knot looking protuberance, will occur.

That plant is imo not very old. Do any grafters/nursery folks think the same as I?

Dax

Dax, I agree. And sometimes the lower part of the scion does bulge out, maybe due in part to a callus effect?
With regard to compatability, it does look like there might be a difference, but my thought is the same as what Resin says, time will tell.
Sam, the presence of buds does not concern me, but please keep us posted on this, and the graft union!

On a related note, here is an abies concolor scion (on concolor understock).
I had given up on this one (grafted earlier this year) since all the needles had fallen off and no new shoot developed from an existing bud.
But this weekend I noticed multiple buds appearing, which may be considered advantageous.
I used to think you had to have live needles on the scion in order for it to take.
But this year I've had a few instances where that was not the case, either by chance or design (i.e. I plucked the needles off the scion prior to grafting).
On this scion, you can almost see two different sections, one live and one dead.
{{gwi:698904}}

Agree with Resin, too......

Nice score Nate. There's definitely a noticeable difference among dead wood and live wood as... your picture clearly shows us, i.e. tight/shriveled vs. wood with "water."

Dax