I teach game desing using Pico-8, and we ran into a lot of problems with version mismatches, the well known "future version" nag.

Can this check be removed? Worst scenario is that a game throws an error on a non supported command, which is 0.0001% chance of happening with the basic stuff students create.

see accept_future here: https://www.lexaloffle.com/dl/docs/pico-8_manual.html#Commandline_parameters

So I type that in config.txt? All other config items do not start with -

no, the command-line parameters are parameters to the program, not config file params

would it not simpler to update all versions? pico8 isn't a big program....

Unfortunately not. It is rolled out in school on hundreds of machines. Everytime a student works at home and the web editor has a new version, they get into trouble back at school.
Where to enter that command line thing? It gives an error: syntax error near "-"
In Terminal it says -bash: pico8: command not found

For now I let my map editor I use for grading write all .p8 files as version 25. That way they always work.

If one would manage to enter the command, will it change the config.txt? If so, what would it say after you enter the command?

Did you add the argument? It would need to be run as e.g. "pico8.exe -accept_future 1".

I don't believe it will change the config file, because it isn't an option in the config file.

> Where to enter that command line thing?

that depends on where you installed pico-8 and how you start it!

Command line argument should be in the executable if you right click and go to preferences. It's a godsend for bypassing splash screens when booting steam games that feel the need to spend 3 minutes telling you who made it

On the Mac, I double click the app icon. Passing the argument to the app itself in Terminal is not working. So there it is: a feature request for the MAC version. Preferably in the config.txt or just throw it out completely and make it a warning instead of a conputer-says-no situation.