Some doors do not open to certain monsters, that is how it is currently. As to the 'loss of consciousness' mechanic, yeah, some monsters have limited time to play as player-monster... This mechanic may change in the future to be more permissive to exploration. Do have in mind some monsters can walk around more time than others!
I would recommend potentially a option that can be unlocked is the option to be able to fully explore the facility while transfurred without loss of consciousness, to allow for interactions and exploration as a bonus feature. It could allow you to hide a whole bunch of interesting secrets and fun things to do with the various forms.