I understand you are worried, obviously you put a lot of energy in this project and want to do everything that you can. I can tell you however, once you have your immigration packet you are good unless you do something really serious in between, like kill a guy, or get arrested for smuggling drugs or whatever.
I was a bit worried too, especially with all the covid restrictions and you know what happened at the entry? Nothing, there wasn't any questioning apart the necessary, if the address we provided is still correct etc.. the officer was very nice, he opened the envelope, put the stamps in the passport and wished us the best of luck.