You want to connect with your admissions officer at smaller schools (i.e. Swarthmore, Pomona, etc), as these schools often care more about demonstrated interest/the applicant as a whole/etc. I think you want to come across as a friendly pest––your emails are specific, you come across as friendly, and you show genuine interest frequently, but not enough to become bothersome.
I think emailing admissions officers at larger schools is a bad idea. They will likely either not respond or reply with a vague, unhelpful message. For example, I emailed one admissions officer a very specific question about a major (and he had this major at the school), and he wrote back for me to contact the academic department. Two sentence response.
OP: If your emails fall into the first group, email again. I agree with @Lindagaf: also send the email to the general admissions office email. If your emails fall into the second group, I’d beg it.