If you can manhandle them, you can reburn. Gotta ask yourself if it's worth the effort though - how critical is it that they don't have scurs at this point? It is much more stressful on them, IMO, to be reburned than it is to burn them at the proper time.
If it were me, and I didn't want horns long term, I'd either reburn or sell these guys. Sounds like at least scurs coming in. Or wait and see if horns (or just scurs) come in. If the horn growth is undesireable, then what I'd personally do is keep some daughters that are disbudded at a proper age, and cull the adults when convenient.
I just did some kids that were 5 weeks old, first burn. We snipped off the growth with a hoof nipper and burned what we could. They weren't mine, but the man who had bought them was new to goats and though they were done older than a week of age or so. Bought 'em as bottle babies from people who do not disbud. He has two small children right at the perfect height to accidentally get a horn in the eye, and he wanted them done. I agreed, his human kids' eyes are most important. We did them, wasn't that bad, but I certainly didn't promise no scurs. I have horned goats and no small children at my house, so on MY property, I probably wouldn't have reburned. Up to you to decide what is best for your situation.
As a second burn, your babies probably will turn out well if you get the growth area well. It was helpful to have a 2nd hand to hold bigger kids though, if you do decide to reburn.