I think my 214 fits too snugly in its case for my leather strap to be laid on top. And the compartment under the fingerboard has too many other things in it (capo, tuner, spare battery, picks…). So the strap folds under the headstock, with the humidifier between it and the headstock itself. Seems simple enough, if fiddly.
PS I also store a spare pair of glasses, wrapped in a microfibre cloth, in the cutaway space. Be prepared…!