There is no Roku player model with Composite (RCA) outputs - The 3910 Express+ was the latest model and they were last manufactured in 2017 and Roku sold their last stock of them in early 2020.
You'll need to continue to use an HDMI>Composite adapter if you want to use them with older TV's with no HDMI input.
Instead of using a stick model, try the Express 4K+ and plugging its HDMI cable into the HDMI>Composite adapter (should reduce overheating).