I have been using 4L2DAKI framework for Sprint Retrospective for a long time whenever I help people adopt Scrum. It’s a mix of 4L, Double-Loop Learning and DAKI.
Basic concept is that for a Sprint Retrospective to work you need easy way to get feedback, easy way to visualize action items and an obvious process highlighting the need of analysis with clear input and output. So you use 4L for getting feedback, DAKI for action items and Double-Loop Learning to frame the discussion and make the goal obvious.
First usage by me start during my days as Solution Architect @ BUILK ONE GROUP and after skipping agile coaching for sometimes, also adopt this when I work as Senior Solution Architect @ Factorytalk.