Will I continue earning interest after my Stash goal is reached or after I passed the Stash target date? I do not have any plan to withdraw or close my Stash yet.

Yes, as long as you keep your money in your Stash, you will continue to enjoy the high Stash interest rate.

If you want to enjoy a better rate, you may opt to open a Time Deposit instead of using the money you have saved in your Stash.