Hi all - I have been thinking of ways to optimize the number of blocks and treadles for turned twill drafts on my spring 2 loom. After playing on fiberworks, it seems that I can get more treadling options if I draft the turned twill blocks on 3 rather than 4 shafts. I gather that 3 shaft twills are used in some Scandinavian weaving traditions and in rigid heddle weaving, but I am not seeing many references to them in turned twill, so I am wondering if I am missing a major pitfall of using three shafts. Any advice? Is there a reason to avoid this? Thank you!