Could those serrations actually be the grain of the steel?
I seldom use multitool blades, favouring dedicated knives instead.
However, I tend to have most knives set with a micro tooth for more versatile cutting as mentioned above - but that's simply from sharpening with coarser stones (like you might use for reprofiling an edge), and not following up with a finer grit.
From my perspective a coarser stone sharpens quicker and cuts quicker - I don't tend to need cleanliness in my cutting, just efficiency. OK it removes more metal, but then I steel the edge between sharpening anyway so I don't have to sharpen too often.
I hardly ever use the blades on my leathermans. I like to keep them sharp just in case. I always have some other kind of knife or SAK for cutting tasks. If I use them I strop when I get home, and hardly ever sharpen them, and if, then just a few passes over a ceramic rod. Just as you say, to bring the sharpness back. The sharpness of LM blades was always great, and the micro serrations never bothered me, I liked them.
The fact that I don't like about LM blades is that often times they have uneven bevels, different angles.
I don't know that it's a belt per se, I wouldn't have confidence in that if I were the Manufacturer. A stone grinder would be a bit more consistent. I could be wrong, I have never been in the factory.
While I do like a touch of 'bite' to my knife edges, the factory finish is still to coarse for me. So it's on to the bench stones for a bit of work.
when I get a new LM tool, I will sharpen it right when I get it.the factory edge isn't sharp enough for my liking.
The micro serrations actually help the knife cut more quickly in most situations because most people use a sawing motion as apposed to pushing the blade straight through the material they are cutting.Having said that, I have highly polished bevels on my CS4 blade because I like the way it looks next to the satin body of the blade. The polishing is achieved by using chromium oxide stropping compound on a leather belt in my bench top belt sander.