I’ve done it both ways. I had to 200 logo Cookies for a local SPCA. I made the cookies and froze them (double bagging using ziploc bags). I would take a couple of bags out, decorate them. While they dried I did another batch. When dry I rebagged. When ready I defrosted all of them on racks and heat sealed them, which took hours. If you bag decorated cookies be 100% positive they ar completely dry. Also, when I freeze them I put either parchment paper or wax paper between levels and then carefully stack. I have minimum breakage, maybe one or two cookies. I’m a bit fussy about my cookies, but the flavor gets raves.
I don’t want to put the money out time into cookie unless it is going to be delicious. I’m not the best decorator, but my cookies always taste the best.