For semi-flexi, if you want to consider avoiding interest during lock-in period, you can do 99% advance payment. My own experience for 400k loan, I paid 399.9k leaving a few hundered ringgit inside, so far so good. It's maybank semi-flexi loan.

For 99% advance payment, the money will go into an accrual account, and monthly payments will be deducted from there. For full advance payment, afaik the account will be closed.