some of my humble observations

1)for the 10rm monthly maintenance fee of full-flex, it is the same as parking 120(per year)/.0335(blr-2.2) = around 3600rm in it permanently (less if blr rises).

2)for the semi-flex since it will cost around 10rm to 50rm per withdrawal of multiples of 500rm or 1000rm, it would make sense to have some buffer of at least 5k or more (depending on your needs) parked at another savings/current account which acts as the daily/regular money moving account.

3)assuming that the interest earned on this savings account from parking this 5k is minimal (most savings account has pitiful initial tiered interest rates) in the semi-flex scenario, the 10rm monthly maintenance is actually free as the 5k in the semi-flex scenario could have been placed in the full-flex account to cancel off the 10rm, more or less.

4)taking the previous example where the full-flex was blr-2.2 and semi-flex was blr-2.4 the difference of .2% would equate to 200rm/100k loan/year.

so to decide which flex is for you the risk assessment question would be this, in the semi-flex scenario would you be able to control yourself well enough to limit your withdrawal frequencies so that the 10-50rm charged everytime over a year is less than the 200rm/100k loan/year that you would have saved?

my 2cents

if mr A can make an investment return of 10% of course he will be richer. however, when he could find no other avenues for investing his other excess cash or that his original investment vehicle has suddenly become unprofitable, he could park his cash in the humble flexi account which at least gives him blr-2.2 more or less before he starts to think of another investment plan and proceed to empty off the flex account again.