If you take the stock config for Ender 3 V2 (out of the configurations repo linked to you above), then you add the things that they have mentioned (arc support, filament change, advanced ok, classic jerk, s curve acceleration, etc.), you reach the firmware build they have on the site. It is worth learning what components you have on your printer, since they can break, need adjusting, need replacing. You should be able to search the keywords in either Configuration.h and Configuration_adv.h files.
So what is said here is NOT in the provided config example? Are the 'Adds' there? For a new person who already has trouble with the terminology of the printer this is real confusing. The printer itself is not confusing. I am familiar with all the parts I see and have repaired my mainboard also. The terms for how all of them work is confusing. I am a Retired IT professional and have programmed an STM32 in the Blue pill, so basic programming is not the issue. It''s the terminology and the sheer number of all the things to worry about that makes it daunting.
Honestly, I suggest you tell all this to the firmware page you are paying money for to use. We cannot make them mark up stable releases (which frankly they should really be doing, precisely for reasons like this), we can only tell you the basic steps and places to collect the information that you need to do it yourself. We don't have your printer, we can't do it for you, and the place that does it for you seems to only do it for you for potentially broken nightly/development builds. We cannot fix that. We cannot fix the current issues with nightly builds of the firmware either. As I said, I understand this is a frustrating experience for you, but we can't do more than what we already have. You may continue to run nightlies as well, but from our current observations here and on discord nightlies currently aren't as stable as they should be, so you might run into issues with OctoPrint or any other host software.
USB cable issues are well known on the Ender 3/Pro. I found isolating the +ve on the USB cable at the Pi end solved no end of comms and connection problems, and have maintained this since. There appears to be an issue with ground loop/bonding somewhere in the Creality design which means the reference voltage from the Pi or the Printer is dragging things high or low. Not to mention connecting the +ve leaves you open to undervoltage brownout's on the printer side (shouldn't happen but haven't tested) dragging your Pi low and creating other issues. (I found the dryer in the laundry on the same circuit was enough to cause issues... Which I'm assuming is the brownout bit on the circuit Pi or Printer I don't know.) What I do know is once the +ve was isolated between them it's worked like a dream.
My Printer and Pi are on separate power supplies but from the same power board. Also found a wall wart on another device was creating other issues relating to ground and signal voltage noise too. So there's a list of things outside the Pi and OctoPi that could be causing this.
Thank you, I have TH3D's blocker on my Pi. I also just switched to a Pi4 with a fan on it so maybe keep the Pi from getting lost. Haven't printed much since starting the swich yesterday.
i was running my Ender 3 on a Rock64 with Armbian and it would randomly halt with serial com error, destroying the print. out of frustration i took an HP Z200 workstation, installed debian, docker, octoprint container and never had issues again. i dont think those little Arm computers are a good choice for serious 3d printing. if anyone is interested, i can make a guide with docker on debian, and single click printing so you dont even need to log into Octoprint to initiate prints.
Update: i now have a print farm with 12 printers, had several defective USB cables that caused constant serial com error. if you have this error, try a different USB cable as a first try
Always a good Idea to check the ground in your printer. I have checked mine. I have cheap polyester carpets, if I walk up to the printer and touch it, it can kill the print, so I have a grounding pad on the table in front of it which I touch before touching the printer. I have to do this with any electronics in my house.