Burnishing, finer SP, plastic polish, buffing - will all get a better finish. The difference comes in more with experience than anything else. The experience is needed, but you won't exactly know until you can visually tell.
Get a "very good" quality magnifying lens/loupe, and get a good quality bright 5000K light (or take it outside into sunshine) and look for scratches. Find a solution that wipes out those microscopic scratches that are not visible in normal house/shop lighting.
There are those that swear by buffing, but buffing requires its own techniques, or it will destroy the finish. Buffing WILL get you what you want but your technique and experience is what gets you there.
Plastic polish and waxes will too, but again your technique and experience is what gets you there.
20,000, / 100,000 SP will too, but it is your experience that makes it or breaks it.
So, fundamentally, how will you know unless you can regularly inspect it. A good loupe/magnifying glass and great "daylight" light.
I haven't counted "layers/coats in 12 or 13 years. For Mea, it is not a matter of how many coats, it is a matter of how MUCH CA is there. Some people will put a thick drop of CA on their paper towel (PT) and get a single thicker build up as the blank gets a good dose of CA directly; others wet the PT good but all of the CA comes from within the CA for a fraction of a second. This means that "Coats" thickness is an inexact science because of individual technique / application differences. However, measurement by calipers is an exact science.
I, and some others, apply CA directly with a non-absorbent applicator. Coat thickness varies, but we are not concerned about how much each time but how "much" measurable is on it. With specific applicators, we may not put but two or three coats, and as a result have a thicker build up than others do with 10 - 15 coats with PT.
That said, it is choice of individual technique. But when it gets down to the final finish, a loupe/magnifying glass and good light is what determines the outcome. My tag line is: Good is the enemy of Best.