Hi Terri-Anne, I hope this conversation takes off, and EVERYBODY weighs in with their thoughts. It’s a subject I am very interested in, as well. When I think of loose painting, I often think of bigger brushes. But bigger brushes require bolder decision making, and so, in reality, it’s probably a combination of those two that gets me to a looser painting. When I read your thought about “A progression to abstraction?” part of me said Nooo!!! but then I reconsidered the various definitions of abstraction, and there are some that fit 
where quality vs quantity of abstraction comes into play