This code does seem to work, or at least, I have it working here: http://spellout.net/ibexexps/leaena/test/experiment.html
However, the way that I understand to implement it is to copy the template and make one template for each type (a, b, c and d in my case). If I just have one template and name it “items” or something, PennController.Sequence does not find things named A or B or C or D and so it thinks there is nothing in the running order. However, when I copy the template 4 times, even though I use .filter() with each one so that it should only apply to one of the types, it repeats all of the items …twice? I am not sure if I’m doing something wrong or if it is not working the way it is supposed to. Probably the first. :]
Advice would be appreciated!