I get my best P4P maps with 360' AGL 90% front overlap, 84% side overlap, 9 mph max speed on an overcast day with low wind conditions. I can cover 20 acres with one battery and have 30% remaining battery energy on landing. Try a few missions with difference settings (75% and up, 9 mph - 15 mph, 200; - 400' AGL) and check the reported RMSE for the mission. To see the RMSE in DroneDeploy, click on the Title of your mission in the first screen after you select the mission from the Dashboard. My best RMSE has been 5' with X = 8.1', Y = 2.7', Z = 1.7' for missions flown with long E-W legs.
Do not go for 34 mph speed as this requires a very fast shutter in full sunlight. Full sunlight does not give me the best results. The more uniform illumination of an overcast day yields maps with lower RMSE and fewer holes in the 2D and 3D maps. I have yet to have good results with 15 mph speed. So if you can keep the speed down and complete the mission on one battery I think you are better off.