and two more thoughts

- would be nice to see a more explicit explanation of how the  chunks (are
you proposing that chunks become a specification?) fit in the
ACT-R architecture, and how ACT-R fits/reflects the cortex/cognitive
function

- since ACT- R is a very abstract model, would be nice to see an analysis
of how the demos implement and validate the model

(sorry if this is obvious)   can ACT-R   valid in real/useful in the real
world and can the demos help to identify also its limitations?

Related article

  Representational Limits in Cognitive Architectures
http://ceur-ws.org/Vol-1855/EUCognition_2016_Part4.pdf