Is it bad to rely on manually cocking a DA/SA trigger?

background: I’m new to guns and am starting with a nightstand gun, an m9a3(F), to learn with. It’s my understanding that because it’s big and heavy it’s better to learn with than an easily concealable gun. I really like the safety value of external safeties and the DA/SA triggerBut for the home defense side of things, is it a bad habit to practice turning the safety off and immediately cocking the hammer for the SA pull?and separately would that be bad practice for concealed carry if it can be done fast and one handed?and is that bad for the gun in any way?I never see anyone mention cocking DA/SA guns here, it feels like an obvious featureEDIT: follow up out of curiosity, does anyone know why do they have the cocking feature? via /r/CCW https://ift.tt/2CGdu0K