- Add a "Preview data" option if you right click the step. (it will launch a preview run) Selecting a step and hitting the preview icon/menu will do the same, but it's never exposed in the GUI so people don't know about it.
- Add a "Clear log before running" checkbox in the execution dialog. That helps in the detection of errors in the log. Enabled by default please.
- After a failed run, we can add a visual indicator in the transformation graph next to the failed step, something like a "(X)" icon in red. Mousing over that icon will show you a rich tool tip with the error log lines. That would help you since you don't have to switch tabs at the bottom anymore.
- Prevent the tabs at the bottom from switching focus when you run/preview a transformation.