When you are used to the gnu tools (like you), you are likely to see that as how these tools should work everywhere. When you are only used to busybox, that is not the case.

Afaik the developer of smscon was not aware that gnu ps had a different output. We worked out a solution so it worked with both, but I can't blame him for not considering gnu.

The idea of a small toolbox for limited devices is okay imho, but the incompatibility indeed it is a real pain.