Need help to finish Pax Klanq quest

I found the "center of the forest", or something similar like it, and I took an Eater's Flesh mushroom. But I didn't eat it right away, I was fighting off the sludges and got carried away a number of parasangs. I ran away from the mushroom forest in terror, to return back after I have gotten more levels.

Now I don't remember where the center was. I can't find the same spot, all screens here look the same. The corpse on the floor is gone, perhaps it was burned away during fighting. I have entered the forest again and ate the Eater's Flesh to become shimmering but there was no yellow/orange road anywhere I went. Then shimmering ends eventually. I tried it a couple of times from many directions and even used a wish to turn sludges docile to save time — but there is no road to follow anywhere even though I shimmer for many-many screens I travel at random.

What should I do?

(Little rant: This quest is so prone to soft-locking you out of the game progress, it is baffling. Quest log doesn't tell you the parasang where you should start shimmering from. "Center of the forest" message does not appear second time. The fact that you have to eat a certain food is not telegraphed at all. How a new player can even know what to do here is just beyond me. I had to read wiki for a guidance, which sucks from immersion point of view, and even that didn't help to finish it. I don't understand: should I eat Eater's Flesh on a specific spot, or can it be done anywhere? Like, who beta-tested it all?)