In my experience, 27.455 USB / 27455 USB is the de facto Latin American SSB calling frequency (along with several others, including several you listed like 26.215 MHz USB / 26215 USB and 26.225 MHz USB / 26225 USB.
They also make heavy use of various frequencies in the 27600-27800 region, USB and LSB, with activity centered around 27.665 MHz USB/LSB, 27.695 MHz USB/LSB, and frequencies near these in 5 kHz steps or 10 kHz channelized (export radio) steps. Seems like a sizable amount of these operators are using modified amateur radio or ham radio equipment on 11 meters and therefore have a VFO instead of an export 10 meter radio with 10 kHz channelized steps + a clarifier (+ or - 5 kHz) and maybe a +10kHz switch to get complete frequency coverage over a radio's given range.