I’m sorry, but the Doolittle Raid was very much “consequential”, in two militarilly applicable (so setting aside the morale impact) ways: first, the Japanese drew a significant number of aircraft and their pilots, aircrew and support personnel back to the Home Islands from the combat zones as a hedge against the US trying something like it again and second it gave Yamamoto the argument he needed for the overreach of Midway.
To your post I would add..
Third it was a shot in the arm for our nation. We were reeling from our losses up to that point with no sign of any victory on the horizon. It was the first time we bloodied them and we rejoiced in the action.
Forth it made every Jap look up when planes were overhead, even their own, and wonder if the Americans were back. Masterful psyops.
Whatever influence on Midway, the Doolittle Raid might have had, it was too indirect to be consequential and that battle turned mostly on very bad luck for Yamamoto, IIRC, in having the wrong planes refueling on the deck at the wrong time and not on overreaching by Yamamoto. Don't war gaming replays to this day show Yamamoto’s forces doing much better than what actually occurred at Midway?