What I would do (it's your suit, do what you want) is fill where I wanted to, then try to match the paint color and since that may prove difficult, add weathering and black wash to help blend it.
Does that make sense?
That's the whole thing I'm trying to avoid.
My weathering was done with a sort of "A.O.E." effect by a classic black wash of slapping on watered down paint and sort of "smearing"/dabbing the watered paint, leaving most of it on. Trying to do it to localized around just the gaps that I filled be prove difficult to get it to work properly. What might happen is that there could be a black wash both on and around the lines that I filled, which might look inconsistent with the rest of the armor.
The only reason I don't want to match the paint and weathering of the filled the gaps with the rest of the armor, is that I'm worried about messing it up and having to repaint the whole thing over again.
Now, I would have beveled the lines properly from the start, but was (and still am) a broke as crap college student. I was only able to buy a proper knife to replace the pocket knife I had only afterI won a campus hosted costume contest. However, at that point the armor was already built.
What I might end up doing, is fill the gaps, sealing it, and try painting it black. If the black looks wrong, I'll re-seal it again and try painting properly (the way I did the rest of the armor).
Either way, I'll fix the issue and try my darndest to not make it look like a goth clown . . . Nobody likes a goth clown