There is an expert around who posts as
@azu
Ask him if you dare. But I warn you he's a cranky, sarcastic, patronising git who will make you feel stupid for the way you ask your question, and God help you if you do any research and try to pass on what you learned!
At some risk of attracting his attention, I'll have a go...
Lodging the application first is sufficient to establish that we were first with the invention. That protects us from anybody else using our invention without licence, or getting a patent before us. You can't take legal action against violations on the basis of an application. But once the patent is granted (or allowed) you can launch proceedings for violations that occurred after the application was lodged even if it's before it was granted.
If our application is rejected then it's pretty much open slather for anybody to use the idea, or even attempt to patent it themselves.
I wouldn't sweat over the granting. If we identify a violation then we can try to expedite the patent process and launch legal action. Otherwise, left to take its own course, it could take years yet.