Sketchbook shorts shortening/lenghtening and errata page not found

I'm going to sew a couple of sketchbook shorts as school uniform for one of my kids. I will probably shorten it for the summer uniform and I would love to lenghten it for the winter version. Will proportions be nice just lenghtening the shorts? Which will be the best point to make the lenghtening? I also want to make the shirt, upcycling old shirts from my husband. I have checked the link to the errata page, but it doesn't seem to work. I think the version I have is not the first one, but anyway, I woul prefer to check if my pattern has any errata.