gray shore
I don't know if anyone else has noticed, but the quality of brushes has seemingly taken a nose dive. The following method will not work on synthetics (it just makes them curl worse). Its based on watching videos of Japanese and Chinese brush makers.
What I have noticed is sometimes the animal hairs have very long thin whispy 'tails' and these can touch the model and provide enough pressure to cause the point ( which is carrying the paint ) to splay slightly, which makes painting more difficult.
There is a stage in Chinese/Asian brush making where they use the edge of a knife scrape against the point of the brush for some brushes. This is usually done before final assembly and I suspect its there to trim off those whispy bits. They're not cutting across the hairs, but more like dragging or pull them over the edge of the knife.
So I took one of my cheaper animal hair brushes, plagued by those whispy hairs, and I flattened it between between by thumb and curled forefinger. Then I opened up the jaws of one of my sharp model nippers, and I drug it repeatedly across the tops of the hairs, using my thumb to drag the hairs across the blade. I made sure to rotate the brush occasionally.
Eventually any overlong whispy hairs will disappear. And thicker hairs that stick beyond all the others will be shaved down.
Get the brush wait occasionally and check progress. I think you will find after about five minutes, the hairs will splay in a slightly curved, but form a sharp tip when wet. You know you're getting close when each time you press and spread the bristles they splay out more evenly.