Re: formal "class" as a supplement to keiko?
To me it's always staggering to think about what beginners must learn before they understand what they are doing and why in the dojo.
The interesting thing is that there is no mechanism set up to teach them. If it get's taught it's because individual instructors or students pass on what they know rather than a formalised system.
For instance a beginner might ask why they have to bow. To them it's just bowing. To someone more experienced the beginner has just opened the door onto the rather large topic of reigi which the beginner, as yet, is almost totally unaware of.
If I'm trying to get them to do ikkyo I don't have time to explain the ins and outs or reigi to them, but they want to know. The only time I would have time to explain everything is at the bar after training, which seems to be a sloppy system to me.