Plus it makes Luke’s rejoining the rebels during the briefing difficult to handle.
And I say that as a proponent of the idea.
The other problem is, you can’t really break up the stuff on Dagobah. It’s really just two scenes, talking with Yoda and then talking with Ben. But it doesn’t make sense to cut away after Yoda’s death because if you want to cut back later to the scene with Ben, you’d end up wondering “well what has Luke being doing hanging out at this dead guy’s house?”
I’ve seen the idea knocked around to somehow do a background replacement and make the Obi-Wan scene take place on Tatooine/in Obi-Wan’s hut, but that seems…difficult to pull off at best.
Or you could just cut the entire Obi-Wan scene and not lose too much, perhaps.
You could always move the Ben scene to Endor right before Luke turns himself in. It wouldn’t take nearly as much work to make dagobah look like Endor.