◇ Could this help me?
Yes, and the distinction between a handoff and a compaction is a genuinely sharp one. Compaction compresses a conversation, which means it preserves the structure of how the work went, including the wrong turns, while a handoff file states the facts of where things stand and deliberately discards the path taken to get there. The what-has-been-tried-and-failed section is the part that makes it work, since a fresh session with no record of failed attempts will cheerfully repeat them, and that is the exact situation the technique is designed for. General practice, and the natural pairing is with clearing at task boundaries: the handoff file is what makes a clear safe, because it captures what would otherwise be lost.
Before we end this session, write a handoff file so a fresh session can continue without inheriting this conversation. Include the goal, the current state of the work, the files currently in play and what changed in each, what has been tried and did not work along with why it failed, and what the next step should be. Be specific in the failed-attempts section rather than summarizing it, since that is the part a new session cannot reconstruct and will otherwise repeat. Write it as facts about the state rather than as a narrative of our conversation. Then tell me what you deliberately left out and whether any of it is worth keeping somewhere more permanent.