I think it depends on your definition of "high SDI"... are you talking about the normal spell books with like 12% SDI? If so then yes this is made by a scribe and the mods are 100% random in number and intensity (I think 12 SDI is max on a normal spellbook). Are you thinking "high" is 25% SDI on the scrappers? If so all of those come with 25% SDI as a default as long as you have the recipe you can make that (you are hoping for a random good slayer there). If you are talking about 25+ SDI then you are referring to the invasion / event spellbooks which can't be made. Over the past few years the up to 30% SDI books have been a somewhat annual event around Halloween time (latest was at Khuldan, year before that was Mages dungeon, year before that might have been Kotl?) but I think the only time the up to 50% SDI was a year or two ago invasion (killing mages got them) and you would need to buy these (or wait for the next invasion!).