Has the Graal bug, which allowed completing it in one day, been fixed?

I remember about 15 years ago, someone posted a puzzle map on hiroportal.net. It included a bug, in my opinion, like building the Grail in one day. That is, the condition for winning was to build the Grail on the very first day; otherwise, you wouldn't have time and would lose. According to the explanation at the time, this "feature" involved speeding up the hero and then slowing them down: the remaining movement points must EXACTLY match the total movement range. I still haven't understood how to use this, even after reading the explanation, and I haven't been able to pull it off. For example: we start the day on pegasus with 2000 movement points, slow down to 1500 movement points for the hero on dwarves for the next day, and can spend 500 movement points digging the Grail with the remaining points. On the next day, 1500 movement points? And here are some related questions: have they fixed this issue in HotA and Heroes of Might and Magic V since then, and does it work in multiplayer in these versions?