Even though I've used 2D drawing (Illustrator) for years, locking/unlocking end points, lines, etc. is something that has not been intuitive for me starting 3D drawing from zero. Actually, I wasn't even sure what those little locks were for in the beginning (chuckle!) I think that a separate, simple "complete beginners" tutorial showing behaviours of locked and unlocked points, lines etc., perhaps with a few examples showing "if you want to accomplish this, lock/unlock this or these points" might benefit complete beginners to 3D drawing. Of course, I may be a bit of an anomoly or outlier as I've noticed that many folks already have some exposure to 3D.
I'm really looking forward to the new tutorials and to Ver. 3. I don't think you guys ever sleep! Thanks for the great app.