early arm pull can definitely be the result of being out of balance forward. fix your balance problem, and that will likely resolve itself.
keeping the halting DLs to weights that you can do them perfectly or it completely defeats the purpose. if you take it past this point, you are just continuing to train the problem. if you do heavier sn DLs, same rule applies: if you can't do it right, it's too heavy.
try warming up your snatches with a halting sn DL + snatch to further ingrain that proper movement/balance. you don't have to stop snatching heavier than that point, but you do have to work to make every snatch correct, and do more volume of good reps than bad.