Not really because ads are between 10s and 20s (different for each player) and it also takes an unkown amount of time to load, thus the 4s extra buffer.
And isn’t possible to synchronise time after loading of the app? Approximately you have several seconds during which the time of the ads can be synchronised and you can have the length taken as the longest ad delivered among players.
What about putting ads during matchmaking time ?
Whe have to wait several seconds during matchmaking. What about using this time to show ads?
This would optimize waiting time.
But yeah we lose the ability of paying to skip ads but I don’t think you can earn a lot thanks to these payments.
There is also an empty area at the top left corner above the chat.
I would like to fill it with either ads or statistics. 
Just some ideas.
I’m rather happy with your last update. I prefer to wait minutes a day and know that the Hidden Monster Games society is cost-effective, more profitable.
I agree with Masimoto who said yesterday that to gain more money, improving the game is the only good way and forcing the players to watch ads is a mistake.
But it is easy to say. I think that all developers are doing a great job here. The game is clean.
I don’t know much about the metrics, about the analytics. I don’t know whether more and more people play Cfp or not. And I guess that if you decided to add ads, that’s because this was the only way to keep Cfp online. So I currently worry a bit about the health of Cfp.
As you wrote in the last update, the community agreed with ads integration for months. And it seems now that they just understood that yeah ads is a waste of time and now they are finally against it. Hmm. I prefer being able to play Cfp and watching ads than not being able to play cfp because the game wasn’t profitable enough to pay the dev team.
A lot of players are here because they used to play Cf2 or Cf3. The community doesn’t really evolve and it seems that you struggle to catch new players. There is a work to do on communication. Maybe paying popular Youtubers or Twitch streamers could be profitable… But it’s obvious that you already thought about this possibility. 