1 is enough with E
doesnt really matter with 150mg a week, 150mg at once is not gonna spike your estrogen significantly or whatever
splitting the shots further does make sense with cycles / higher dosages, but with just 150mg i wouldnt bother
id hate to stick myself for a measly 0.3ml anyway lol (you can easily use insulin syringes to inject though if youre lean, would highly recommend that for TRT purposes)