this is no diff than the typical method of using filler for the seams. the seams become dark and as there are annoying and difficult drips and runs with those that have to be removed from the panels, just take a little more care with the more obvious and more staining black. use a filler (say fibers) as well to reduce ability to run and mask off the seams to really cut down on problems. and like others have mentioned, keep the hard outside edge on the panel in order to keep line integrity.

if you are going for a real black seam effect, possibly consider reverse bevelling panels to say half depth that have less angle to each other in order to semi-maintain the seam thickness. in one boat, i even put in a few partial false seams in order to continue a few lines i wanted to resolve, so could do the same and play a few games with the black lines.