I carry my Deck in a slightly larger third-party case — which leaves room for a foldable keyboard, Microsoft Arc Mouse, cables, and wall wart + power bank combo. My take is that I rarely need a laptop, but I always carry the Deck anyway — so it’s nice to always have some sort of minimally usable computer on hand. If I know I’ll need a portable computer in advance, I bring a small USB-C monitor.

You already pointed out that if you print it then there is less concern if the case is damaged.

The counter to the ease of pulling it out to game is just that the design of the clamshell could be modified to allow the keyboard attachement to be easily removed from the Deck instead of the Deck being easily removed from the attachment.

I think that would run counter to the point of this build a little. As it seems like the whole point is to still let you just pull the deck out to game on it normally, and protect it while you travel so more integral would make both of those objectives harder to pull of as neatly.

Is however a direction I think I’d rather go as well, if you are already making your own back panel for seamless integration it doesn’t matter as much if it gets beaten up you can always make a new one, and make it in more durable/shock damping material combination. I don’t know of anybody that has just printed a new shell, probably a bit thin walled and warp prone to just print the file provided. But plenty of aftermarket shells exist, so you could use the injection moulded off the shelf case part as the skeleton to build from with the provided model ensuring a good fit to your additions.

For what it is it is a perfectly good screen, sharp enough etc. You probably need good eyesight to find it comfortable and practical to use when it is sat on the desk so probably a meter or more from your head as it is here as otherwise you are sacrificing quite a bit of stuff on screen to make everything large enough for your eyes.

But I’ve used mine in similar fashion just sat on a desk with a keyboard and it is fine, obviously you really miss the larger monitor/dual monitor setup you are used to whenever you don’t have it, but it is a big enough and good enough screen to use as a desktop like system just by adding the usual HID devices. Really not much different to any smaller laptop in usability, you just have to adapt to work in the screen space you have.

I use my SteamDeck when visiting my parents, friends where everyone has at least one workplace with USB-C dock ready. I hate puny laptop displays and non-orthogonal keyboards from the bottom of my heart anyway. So I say that even 17″ displays are barely usable and not comfortable at all.
There are just a few occasions per year when I would appreciate having laptop like devices and suffer through using a small screen and that’s where a setup like this one could come in handy.

If so then I bet a way better/compact version can be made while integrating it into the shell itself.