See Biur Halacha simon 639 seif 2 paragraph starting Im Kova
Kvias Sudah in Sukka is not same as kvias seudah to require Hamotzi. For Suka the individuals Kvius is enough. For Hamotzi universal Kvius is required.
Skverer Rebbe ZYA (& his son YBLCT) when he went to sleep in his “sleeping suka” treated his meshamesh with a chunk of Mezonos so that he can be Motzee him with a Brocha on the Sukkah.
See MB end of SK 16 where he advises one who makes alL she Bsuka on Mezonos to spend some time there as well to avoid Bracha Levatala. It seems that the MB was more comfortable with a bracha on stng than on just Mezonos