[raymo]

Definitely, the more subs you can stack, the less noise you will end up with, but more importantly, if you are not taking darks then it is essential
that you enable in camera long exposure noise reduction and high ISO
noise reduction. Unless you are shooting in extremely low ambient
temperatures you need darks; whether they are taken separately, or automatically by the camera is irrelevant. The main reason that most imagers recommend taking separate darks is that it saves a lot of imaging time. Using in camera noise reduction the camera will automatically take a dark sub of the same duration as your light sub, thereby halving your available imaging time. One advantage of in camera
noise reduction is that you know that the ambient temp for the light and dark exposures will be the same.
I don't recall whether you can stack in Lightroom, but if not you can download Deep Sky Stacker. [it's freeware].
raymo