Fast changing booth in rocket silo...

[Factoruser]

You shouldn't require to take off all of your stuff manually, just jump in the rocket and lift off. Your equipment/inventory will be stored separately for each player, for each planet, and gets restored when you return. Perhaps you might have to touch the rocket silo to get your stuff...

[Muche]

An issue doing it automatically is people would be confused as to where their stuff has gone.

Also, suppose you have in your inventory bunch of plates, circuits, machines and a rare tank full of rare equipment you intended to take with you on a new planet. Now it's all in a limbo.
Plates and circuits would be better used in the existing factory than stuck in the limbo while you are offworld.
Machines could be used in a future expansion, but that might be hours away. If you've prepared robot network properly, you might not need to return, ever, managing everything from the remote view.
And you really want that tank with you.
So now you have to drop back to Nauvis anyways, sort your inventory, launch plates/circuits/machines/tank up, leaving only junk you don't mind having in limbo.

[Factoruser]

An issue doing it automatically is people would be confused as to where their stuff has gone.

=> Tips&tricks popup... Maybe a first warning/query that you will leave the planet without your ammunition and the stuff in your personal inventory.

If you don't want to save your inventory, you'll empty it in some provider chest first.

If you don't read the manual, it's your... adventure.

[trancexpress]

An issue doing it automatically is people would be confused as to where their stuff has gone.

Could be like an addon building that does this automated inventory management.

Personally I've started not keeping anything with my character, cause of the inventory and travel hassle. I use remote control roboports and spidertrons.