Almost like described there. But I wouldn't allow to use/prepare a map seed. U can disable biters, cliffs und put all ressources to max. Then click through several seeds. The timer starts in the moment, when u start to generate the map preview. The timer starts over every time, when u create a new map preview, because the one before wasn't good enough.
If u have to transfer the map to a multiplayer-server: The timer pauses after pushing the "game-start" button. Then transfer the game to a multiplayer server within 5 or 10 minutes and the timer resumes on the first frame on map.
That would force u to adopt all of ur plans to the needs of the map. Otherwise u could be able to find the "perfect" map and "perfect" build-order by AI and thousands/millions of simulation-runs @2k ups/min on several instances and after that, just use a clickbot to present the result: Rocket launch within ~45min?
I don't want to say, that u did like this. But it's going this direction. This time, u automated map generation/selection. Next time, u will automate "generating" a map string. Then an AI will find the best arrangement of buildings, after that, the best build order. And in 2 or 3 years, the speedrunner hast just to follow a "click-order".
I can understand that speedrunners hate RNG, because the rsults are more difficult to compare. If u are luky, u could be faster then a "better" runner. But that is sports. All real-world sport-results are at least a little bit RNG depended (e.g. wind).
It would be something different, if that category forces everyone to use the same map-exchange-string.
Again, just my opinion. And I have the opinion, the the team did a great job and put a lot efford in that run.