If both Haema and Bewitchment are installed and you turn into a vampire the Bewitchment way (getting bitten by a Vampire while holding a totem of undying with a certain curse) then both Bewitchment features (e.g. being hurt by garlic) and Haema features (e.g. vampire hunters and the dash ability) are active however when you turn into a vampire with the blood injector that is not true (e.g. garlic doesn't hurt you}.

Another thing I noticed is if you bite a spider you get poisoned if you turn into a vampire via the blood injector, but not if you turn the Bewitchment way