Have you read the requirements/instructions for the petition? You need evidence of having met in the prior two years, for one. This is best done via passport stamps/boarding passes etc. Extra fluff, such as snapshots and chat logs are not required or even recommended in most cases.
The question about the consulate is not a frivolous one. The type of "front-loading" you are suggesting is appropriate for some consulates, and not relevant to others. And the reason to consider that prior to the interview, is that unlike spousal visas, you will not have the opportunity to add subsequent "relatiohship evidence" to a K-1.