One man's opinion. DST does not serve to save energy like it did when started during the First World War to provide daylight for manufacturing companies and save lighting cost since now most factories do not have skylights and run electric lights during all working hours. Although it does appear to effect bar and restaurant sales.
For a lot of industries and services that require time coordination around the world, time is many times recorded in UTC, Universal Time Coordinate, and the local offset for adjustment to local time or a notation about the local time zone.
You are free to adjust your camera anyway you want, but the use of the DST on or off will adjust the time zone offset recorded in the EXIF.