I disagree,might be worth doing MA first.
that's true
yes. money is fungible. but you will likely almost definitely going to hit BHS. so might be worth topping up MA first. then in future any overflow will go to SA and that overflow is not locked.
if this is a one time top up, there is no difference. but ma and sa are earning 4%. there is no difference in the rate of return.
if you top up ma, it will hit bhs earlier. additional contribution will overflow into sa.
if you top up sa, you will hit bhs at a later date. but your sa is larger, so there is no difference.
if you intend to top up a max of 8k a year, then there is also no difference, based on the points above.
if you intend to top up more than 8k a year, then topping you sa is better.
For a normal person, the ma will hit bhs much faster than the sa hit FRS. when this occur, you cannot top up your ma anymore.
If you top up your ma, your ma will hit more quickly. when this occur, you cannot top up more than 8 k anymore.
if you top up your sa, your ma will take a longer time to hit bhs, you can continue to top up more than 8k till you hit bhs.
But there are many people that support amdk. he always encourage ma top up first