I completed this project back in February of 2020. I'm just realizing that I never posted about it here. The bed had held up phenomenally for the past 2+ years.
This was an excellent little project. It was just a little challenging and very fun. I changed the headboard and added a footboard to the bed by using extra 1x6 boards and elongating the feet about 6 inches to make it work. The construction part of this project (including cutting and assembly) took just one evening. I stayed up pretty late working on it, but I was able to complete it in one night. Painting took a few more days.
One note about the guardrails: the pocket screws split the vertical rails that were rounded off at the end. I glued and clamped the splits back together (note the clamps in one of the pictures), so no big deal. But I would recommend maybe not rounding them as much as I did. If I were to build it again, I'd probably just use my little disk sander to take the corners off, instead of taking off as much as I did using a jig saw.