I suppose on a larger heavy boat there can be quite a load on the whisker pole. But if the same boat flew a chute in the same conditions, especially on a tight reach, and or down wind
in a blow, it is my opinion that there would be more load on the spinnaker pole. I have used my whisker pole as a spinnaker pole and damaged it very quickly. When you pull the guy aft it loads up compression
as the down haul pulls tight. Many boats need the down haul eased to do this but in the process compression on the pole is being loaded and unloaded. With the pole near the forestay there would be a lot of compression. Spinnaker poles have removed masts when broaching the wrong way, I have never heard of a whisker pole doing that. Or maybe I will just stay with my boat. There is a lot less load on the whisker pole than on the spinnaker pole. I have had a poled out 140 headsail in 30 knots of wind and hit 9 1/4 knots with the 28 foot boat.
Others may have different results. The original question, that I answered, was asking about not using a pole.