Probably using league/container was not very good idea

[MekDrop]

If a module rewrites or extends some core functionality, it sadly doesn't work. If module tries to redefine a service it hangs up.

It seems league/container doesn't supports such possibilities.

Probably replacing with symfony/container would be safest bet to solve this.

Such functionality should solve issue how to turn such things like formulize into normal modules again and move some core functionality to modules.

[fiammybe]

ouch, didn't see that one coming. If you think that symfony/container will solve that issue, that might be a safe bet (half the PHP world uses that one). I can imagine that will be a huge PR, migrating from league/container to symfony/container?

[MekDrop]

Probably not very huge (requires only few file changes) but still some extra work :|