As requested by Betfair Pro Trader, here are some charts.
The first is the best continuous data I could get together, covering over 6000 UK greyhound markets from 28th September 2015 to 31st January 2016. This covers a lot of changes with the settings and even trading rules such as allowing multiple open bets on one runner. (Ignore chart title, it is from 28th September)
I have mentioned before that the AUS horses ran a lot tighter on the settings and that early in January I changed the UK dogs to the same limits. So below is the period 3rd to 31st January, cut from the above chart. This period saw an increase greater than 1.5 times the previous 2 periods combined. So far this confirms the settings are now more beneficial despite my concern they may have had a negative impact on activity.