Beitza 9b - Opinion of Beis Shamai by Kisuy Hadam

This point on the daf yomi was raised by R' Menachem Spira. In the situation of Kisuy Hadam, there are 2 issues, one is a chafira issue that the gemara says is not deoraysa since you don't need the hole, and the other is a muktzah issue that deker na'utz hepls for (Beis Hillel is only willing to rely on deker nautz bidieved, but l'chatchila they require afar muchan or eifer kirah). When the Gemara suggests that we don't have to swap BS and BH, because BS maybe is really more machmir in simchas yom tov than BH, but the reason he is more lenient by Kisuy Hadam is bec. there is a deker na'utz so there is no issur at all. It seems that this is not sufficient, as Tosafos points out 8a (d.h. v'eino) that there is still an issur derabonon of chafira for the dirt (melacha shein tzricha l'gufa), and BS is lenient bec. of simchas yom tov. Therefore, the mishna should still imply that BS is more lenient by simchas yom tov than BH!