A way to have Luke have been on Dagobah between ESB and ROTJ without moving the Dagobah scenes to the beginning.
I prefer the scene arrangement in the original because I like the buildup of the first act, and the OT in isolation doesn’t need to have Luke train more, because it’s the original and therefore is free to establish how long Jedi training takes.
However, I think having Luke train for a year works as long as there’s a way to retain the scene arrangement of the original.

Take the deleted scene of Luke turning on his new lightsaber and putting it into R2. Background changed to Dagobah. Then simply wipe to the droids on Tatooine. Rest of the movie goes on as normal.

Luke returns to Tatooine after having spent a year on Dagobah simultaneously training and coordinating the plan with his friends using holograms.