1: I do not know if the double XP multiplier affects only the tracked medal, because when I get a medal, I am usually tracking it to help progressing it more easily.
Thank you for the article about leveling up, I was already doing pretty much all that. I am at rank 126 with around 2350 score per minute played globally. I wasn't sure how good that was so I checked the global leaderboards on battlefield tracker and found out I'm 352th best player in the world for score per minute lol! It made my day! 🙂
Just trying to squeeze more cool XP out of the double XP event. The double XP on the medal is great for that (as long as the medal's goals fit my playstyle). And I should activate the squad boost, I forgot to do that to get the multiplicative effect of the double XP event.
Also, I do not know if double XP applies only to weekly medals or any medal.
2: About your post that your progress bar does not progress from rank 149 to 150. That is very weird. No idea why it happens.