Yeah, he wrote down his adventures. It doesn't mean he wrote down the coordinates of all of the Road Poneglyphs, or even how to reach Laugh Tale himself. Why would he do that? It makes zero sense, and completely undermines what Roger had hoped to achieve with his dying breath. He didn't even tell any of his scabbards any information on Laugh Tale, but yet left it in his journal for anyone to find? That would be some Sentomaru "I am the tightest lipped person on the planet, and then proceeds to spill the beans" level of "bruh" right there.