The thing is, the “ongoing relationship” evidence isn’t required for K-1. The requirement is evidence of meeting once during the immediate prior two years, and evidence of both partners’ willingness (and eligibility) to marry each other within 90 days. That’s it.
Feel free to send what you wish. For some high fraud/high risk consulates (Lagos, for example) it is beneficial to “front load” the petition with additional evidence of meetings, and ONE meeting (minimum requirement) might not be enough. But for low/average fraud locations, the requirements set by USCIS are usually adequate. YMMV.