I have read reports of damage and breakage from boar bristle brushes on hair and beauty forums, I am not convinced there is any science showing they are any better than any other low snag brush. The claims seem to come from companies selling the brushes, for example Kent claim "Natural boar bristle will never damage human hair as they are both made of the same protein."
Completely illogical, human hairs can damage one another through friction!
2a-2c, medium texture, porous/ colour treated. Three years CG. Past bra strap length heading for waist.

CO-wash: Inecto coconut/ Elvive Volume Collagen
Treatments: Komaza Care Matani, coconut/ sweet almond/ fractionated coconut oils, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss Ultimate Volume, various Elvive
Styler: Umberto Giannini jelly, Au Naturale styling gelee
Flour sack towel, pixie diffuse or air dry.
Experimenting with: benign neglect