Despite so much water passing under that bridge it seems users still struggle with the concept of Bambu being in full control of their printer and workflow.
I am a P1S user and I stopped updating and caring about it with the 1.07 firmware.
It shall allow for offline firmware update, which might come handy one day in the far future.
So what’s the deal with this useless topic you wonder?
I am not a fan of this modern way of consumer binding at all costs.
Especially when it comes to tools and a printer is just a tool…
I want to provide a general idea/workflow for those wanting to stick with the old stuff, that’s all.
And for obvious reasons I won’t post any links as this probably makes the Bambu bots take the topic down within minutes - speaking from past experience here…
I stick with my printer but the the idea is the same for the other Bambu machines, H2D excluded…
The 1.07 firmware for the P1 series and those without the forced authentication for the other models shall be the base of operations.
I already posted something in regards to getting the older network drivers and Studio versions but using the right keywords you can find this info with any good search engine in minutes.
Studio should match the firmware in terms of firmware requirements.
So 1.9 something is probably as high as we can go here.
Orca is always an option though 
The biggest hurdle here is Lan Only mode and the resulting downsides one just has to accept.
Ok, shall we try to begin ?
Firmware downgrade if required…
Handy lets you downgrade the firmware but there is a catch…
You need to be logged into your account to get the firmware and install it.
Right now Bambu has not fully closed the backsupport door, meaning if you grab an older Handy version from places like APKMirror or APKPure you should still be able to downgrade even if the newest Handy version refuses to do so.
Check the firmware release notes though!!!
If it says you can’t downgrade to an earlier version than you might have a problem, so best to not update the firmware based on blind faith alone.
Ok, I assume you somehow found the right links and managed to go back a firmware version that does not include the new auth system…
Orca is the way to go…
If you need to stick to Studio for whatever reasons it is best to learn how to use and configure a VM, a Virtual Machine.
In there you can have as many machines as you like and install whatever Studio version you can get your hands on.
Plus it is quite easy to prevent Studio from calling home unwanted.
You could slice and dice with the latest Studio version and as long as printer firmware and the older Studio version won’t complain can print (almost) as usual.
How to make Lan Only mode stick and ensure custom profiles and filaments work ?
Tricky one…
For (very) obvious reason the OFFLINE ways to bind your printer fail more often than what they work.
Double check that all version are matching close enough!!!
Studio gets updates and to get started here it is best to use the Studio version that was current with the installed firmware.
If all fails just bite the bullet and do the Bambu online binding through your account and all.
If you have a working Studio version where the printer works just copy the Config file over Well, at least copy the part into the other config file that has binding code and such…
Once you can access and use the printer reboot the lot and confirm it still works !!!
Now and only now is the time to pull the plug.
Use a an old router to just cater for the printer that has no internet access, configure your firewall to block Studio, restrict access for Studio and printer through your router’s firewall and network settings - whatever fits the bill and your knowledge level.
All you really need is printer, Handy and Studio in the same Wifi network.
Worked it out and and it still works? Well done!!!
SD access…
There is apps for Windows and Mac that allow you to use your account details to start a secure FTP connection to the printer - giving you full access to the SD card.
You can delete old files, add new print files and all that but from there you can’t start any jobs or access the printer itself.
There are some apps that give access to most things you might need but it seems they all stalled and there is no current progress to report.
But those that worked before the auth stuff came around still work on the old firmwares as advertised.
Camera feed…
Bambu uses a third party system to provide the video feed, which comes with rather annoying security features Bambu utilises to the fullest.
While there is few options to access those feeds if unsecured there is none I know of that works as a standalone option on a mobile phone or computer.
You would have to extract the codes used by the API or find one that is hacked to get around those limitations.
For now just accept that without handy or studio you won’t get a camera feed without a lot of nightmares.
Lost code - help needed!
There was a repository about 2 years ago that aimed to replace the standard P1 screen with a Raspberry based option that simulates whatever the original offers.
Added benefit was that it came with BT and Wifi to allow for a companion app to act as the screen and input.
Was only for Linux but still.
Sadly the entire project seemed to have vanished as there is no website any more and the Google Drive links it had can’t be found through a search these days either.
None of my search engines produce a result :frowning 
I know that chance are next to minus 4 but if you downloaded the repo or just the Rapberry Pi files then please let me know if they include anything to find or contact the author!
As always > feel free to ask here if you want more details or need specific help on the above…