Myself, unless they're pubescens I usually leave them in, but like DWB says, just the process of halving them and running them through the dehydrator will cause the vast majority of the seeds to drop/shake out.
I use a coffee grinder (spinning blade type) and it works great for me grinding up the remaining seeds to the point they're visually/texturally indistinguishable. I have the best results not overfilling it and tilting it a little sideways to get the best grind. Plus always grinding immediately after stopping the dehydrator so there's no rehydration from ambient humidity. If I were to feel it worth the effort to de-seed them, I probably wouldn't worry about getting every last one out, trusting in the process to "eliminate" the remainder one way or another.
I could definitely see making a premium powder and removing all the seeds and trying to get just the tasty flesh in the powder, but that's beyond the effort I've put into it and I've been happy with my general use powders.