Thanks again for the suggestion Sharks - I've made some modification to the original model including reducing the level of take profit when additional breakout occurs which I've taken from the "Breakout PLUS" trading talk.
So the issue with my previous breakout model is that, whilst it's making good money over 3 years, the profit/loss result is heavily skewed towards 2015, where most of the profit was made in that year; and 2018 only made $168 - see image below.
After some investigation, it was the position sizing typo in the EA that's causing the issue.
Then with your generous tips on the optimisation parameters, I've also applied the master trail switch and optimised accordingly.
The result is nearly the same as the trend trading model I've posted yesterday, and with better drawdown and more diversification. The testing is all daily timeframe - might test H4 and H1 over the weekend.