I've only used the 4 hour cycle. So I can't comment on if it would be stronger. You're getting more of the plant material. Is that good or bad? I don't know. I use 2 ounces of weed and 3 cups of grain alcohol. Then poor it into a bottle and store it. Just a way for me to preserve my excess weed. One or 2 droppers and you're set.
Recently I have found that the weed still has tons of THC etc in it. So if you want to get it all, then you have to poor fresh alcohol in and cycle it again. Then you have to reduce the liquid down or it will be weak. I hear it isn't worth it to do it a 3rd time.
What you can do is the second wash, filter the veg matter out, and use it for the first wash of your next batch.