Then don't run dumb tests and spam the same thing over and over.
No one is going to be able to tell you how to run your campaigns. They don't know your keywords, your market, your niche, your targets, your audience. Even less will have any experience targeting the French audience with french hashtags or english hashtags for a french audience. There are so many variables that even if someone gave you a step by step gameplan, probably it wouldn't work. No one is going to do the groundwork for you.
You can definitely by more successful with highly targeted converting keywords that get 1% of the traffic of high traffic keywords. No one is going to tell you them
Honestly, I can assure you, the best advice you are going to get is what I gave you: for the long run
In the time we have had this conversation on here, you could have been testing english / french hashtags and know which is working better for you today (might be different in a few months).
I see it all the time, people try to understand everything, plan everything before starting. But starting is the biggest step you can take. Learn as you go, don't over plan everything before you know anything. All that happens if you do, is you waste time as those plans you made when you know nothing get thrown out once you have started and know more.
Please don't think I am being awkward, but I have seen it time and time again over the last 7 years of being in a position where people are always asking me to check over their plans, even if they have paid me money I tell them the same as I told you.