Thank you for clarifying this. I expected that you would always receive instructions to fly the DP in the clearance. So, in the future I suppose it would be a good idea to tell the tower or center that you are flying it? Also, lets say your airplane is not capable of meeting the climb gradient in a given ODP. If you were taking off out of a controlled field in IMC, could you simply request to circle to altitude over the airport? Thanks for everyone's input.
It wouldn't hurt to tell tower if you want, they're probably already expecting that anyway. I suppose if you couldn't make the climb gradient, that'd be one method of departing, but in the FLG area, there are many cumulogranite in the area waiting to bite you; and the altitude and at times, density altitude, don't help if you're already having climb gradient difficulties.