They have a reason why they didn't strictly impose tax, they want to give penalty since the citizen didn't pay the correct amount or not pay before the due. Even you want to pay tax before the due, their system sucks and they will ask you to comeback/try it again tomorrow.
Oh so there is a draw back but it is also too good to be true if there isn't, as we know that tax is important and part of the economy. The draw back stated there looks only normal. It is an act to discipline people. Normally we also have interest as a penalty for paying late and this grows until we settled our debts. If we pay early and then they say to comeback because they have a problem or what, then that is already their fault. It must be okay to delay this way.
If have a choice, I won't live in such country, I want to live in a discipline country.
Would you like to wasting your time and effort just because you want to pay tax?
We sane people wants the same. Though there are still some that can change their behaviour later on from good to bad. On the second one that you said, yes because like I said earlier, tax is important.