Applying market timing to my £50k portfolio

Long-time 80-20 Investor members will know I am always keen to hear your research ideas as they can be fantastic fodder for future articles.

In September's Chatterbox a member asked the following question:

Hi,
Your April article “Navigating market tops and bottoms” which is one of the best you’ve done, in my view, was very thought provoking. Your backtest found that overall performance was similar (total growth) but drawdown was greatly reduced. Wow, that’s quite a result! This type of market filter performance has also been found by other sources both online and in print, and I wonder whether you would go a bit further as it seems to have great potential? For example how would your portfolio have been affected if you were to invest only in high risk or high and medium risk funds when S&P above the 10 month m.a.