I have seen various posts here re dual passport. I hold a Malaysian and British passport. Am planning a trip (stopover to Malaysia) and then Australia, transit via Singapore. So far I worked out the logistics of travelling as below, any advice, suggestions or help is most welcome:

UK- Singapore: UK passport thus enter Singapore as Brit
Singapore - Msia: leave using UK passport? Then enter Msia using Msian passport? This is where I struggle

Leave Msia using Msian passport and enter Singapore again (21 days later) using UK passport. Onwards journey Sing to Oz also using UK passport.

Does the plan make sense or anyone has better suggestions?

Thank you all in advance