Do High Profile Implants Take Longer to Drop?

I am of the opinion that profile has little to do with the "settling" of implants. In my experience saline settle more than silicone. I agree that the size and shape she be exactly right at the end of surgery. After surgery swelling occurs particularly in the muscle (if placed beneath the muscle). Which can change the shape especially in the upper portion. This just one way the shape may be affected after surgery. Have patience. As the swelling subsides and the tissues soften your result will be readily apparent.
Dr. ES

Three weeks is way too early to know if your implants will drop as it takes some months before you have the best idea of how you will look. The #DropAndFluff timing is multifactorial so hard to answer.

High profile implant do not take longer to drop but you may be left with more upper pole given the high profile implants.  I generally tell my patients that by 2 months postop you look good and by 4 months postop you look great.
It does take about 4 months time before the implants settle if they are placed behind the muscle. 
Good luck.