I have lived the experience closely, from both sides, I entered the lottery with a kind person who adopted me and when they gave the results I did not see his name, I thought we lost (but I was not sure) so I quickly decided to be attentive in the sale individual. Far from getting mad, it gave me a lot of laugh, because I expected it to last at least 5 minutes, but literally my pc cooled itself and in a few seconds, there was nothing. I just laughed and said: How crazy.
Fortunately, then they contacted me and said: Hey, we win, if we have the land.
Suggestions: You could run two lotteries:
1 - A lottery for the 3 remaining regions.
2 - A lottery for the 3,000 remaining plots. In this way, everyone will enter before, you can observe the number of interested parties in time and you will not have people or bots collapsing the system trying to buy at the same time. And if you see that the number of stakeholders is too large, I think you will have time to think of a better solution for everyone to join.
Congratulations, I love this project very much, creating things and having buildings is one of my favorite games.
PS: Please don't make resource wars because they always steal everything from me :(