Actually, I think the "pin in the center" is for a couple of reasons. One of the most important is to keep the hinge from being shoved down into one side when you put the surface onto all the hinges. You really do want all the hinges to be equally into the slots on both sides of the hinge line. And it's also nice to have them square.

The most recent ARFs I've stuck together came with the hinges in and the surfaces in place but not CA'ed. One instruction booklet even suggested that saved me time. NO! Not even.... Bad idea! Heck, one of the hinges on that ARF was stuffed almost completely into the wing.

You really should make sure the hinges are not stuffed into one side. I always take the surface "off" and check. Truth is, what I'm doing is checking each hinge and placing it into the side where the slot is tightest. I don't bother with the "pin through the center" but that's because I am so careful. I draw a very light pencil line along the centerline and watch all those lines as I'm putting the surface back on. Some hinges wind up in one surface, and some in the other. That actually makes it easier sometimes to get the two sides back together, sometimes it makes it harder. But even when it's harder, it ain't no big deal.

One thing I have noticed that seems worth mentioning in this thread.... It seems to be a good idea to me to put more than one drop on into "the joint". One never seems to be a safe amount. A second drop after a second, and maybe a third. And then go to the other side of THAT hinge. I want to CA the other side before the CA kicks. The first side application might wick around and seal off the the very center of the other side and I'd have a one sided seal.

Another thing I'd like to mention. I've found it very sensible to run the UltraCote iron over the hinge lines before I hinge 'em up. A bunch of ARFs have had the covering in those gaps just there, along for the ride, not actually stuck to balsa. The CA wicks off everywhere under that stuff. Seal it down and very little wicks off to NAIL DOWN that covering that ought to have been sticking to the wood already.

And yet another.... I watch the CA wick into the slots very carefully. I always try for zero hinge gaps, and even when they're not touching tightly that CA can wick down along the line. I certainly seals the hinge line then, but the first ARF I made wound up with a rather stiff rudder, and the stiff came from the entire hinge line being sealed by CA. CA doesn't want to "hinge" very gently. I've since learned when to stop with the CA, but have noticed that often it's even the first drop that goes everywhere.

It's almost all technique. Every detail. But better technique is what makes your airplane better.