When looking at the log of a build-step it’s quite hard to differentiate between what’s the command actually being executed or the output of the command. The leading "+ " of command input is quite a brief remark.
Therefore I’d recommend to store input and output distinguishable in the logs to allow drone-ui to, for instance display command-input colored blue and command-output colored white. This might improve the readability of the log and also make it quite easy to find the failing command.