there is strangerville items room in gallery that you can use to gain access to all the objects needed to get to mother and you can equip sim with hero trait that lets you use motherplant for your own means (be it normalcy or something else)
that is fastest way to change so far i think
but yes i think toggle would be very nice to just clickity click what you want
especially for those who don't want to play it yet but also don't want to know whats down there
I also wish we could edit the lab a little like even just the ground upward levels inside the lab to add some items