After a slightly minor delay here's for you the list of winners of the past BuildBattle with screens of the plots:
1st place - Zziu (/p v -76;-53)
2nd place - UnsiW (/p v -420;-697)
3rd place - BlueberryTechLUL (/p v 108;-97)
Starting from April build battles will start automatically the 1st of the month every 2 months (1st April, 1st June, 1st August etc) and they will last 2 weeks, you will know the theme from regular broadcasts that you will see in game and on Discord.
Also rewards will be a little bit better with higher value coupons and stuff, you'll see :shrug: