Bug? Emoncms.org not respecting time= and offset= arguments

I’m trying to bulk upload my historical data. Having done some (successful) experimenting on a local server, it appears that Emoncms.org is not respecting any http API requests that include a time= or offset= argument. It responds with “OK”, but the feed is not created.

My intent is to create a consumption/pulse input by uploading a single point (zero consumption) at zero epoch, so I can establish feeds on it prior to bulk uploading my data. If that reveals misconceptions, do tell!