Thank you for your feature suggestion. I agree with you that the ability to exclude columns from the merged/saved output would be a good new feature. (Unfortunately, you are correct to note that this is not currently available).
However, there is something that you can do from within SUPERLAB (not DataViewer) that might help alleviate some of your hassles with "column clutter."
SuperLab allows you to disable Trial Variable columns in the output. If you have not tried this setting yet, then maybe this will benefit you:
Open the experiment in SuperLab. Go to "Experiment >> Trial Variables." In the "Trial Variables" window, select any one of the variables. "Reaction Time" or "Screen Location" are two examples that will probably be available on the list. Choose one. Click "Edit" to open the "Edit Trial Variable" window. In the "Edit Trial Variable" window, choose the "Options" tab. Remove the check mark in the box next to "Save variable's value in the collected data file."
Click "OK" to close that window. Save the experiment. Those columns will not appear in future output files.
Regarding your other comment about formatting data for SPSS, you might want to read through the following thread:
There are several suggestions there from at least three different respondents. The suggestions involve tools other than DataViewer, however.
DataViewer treats the SuperLab output as a two-dimensional grid, and "transpose" is currently the only transformation provided. I believe that what you might need for SPSS is something more like a "pivot table" than like a two-dimensional grid. Is that correct?