Most airlines use airlineapps or similar service these days. They set their parameters what they want based on the current market. If you’re below the threshold for consideration then no one will see your app until either you update or they adjust their search parameters. That way no one’s time is wasted rifling through applications or resumes that aren’t competitive. It has been said in the past that some airlines even like you applying early because it shows motivation and interest. I doubt anyone really cares these days as they’re all looking for as many pilots as they can get. So no, it’s not unprofessional. Apply now and keep updating as you gain experience.