this threads has been inactive for quite a long while. However, I'd like to restart the discussion.
There are two alternatives for improving the usability of the repeat tag. 1) If the repeat tag arguments could be populated using white pages and a filter similar to the possibility for workflow, the user would be able to add several inputs at once. 2) If workflows would allow for using multiple (but not fixed number of) inputs obtained via white pages as input of a repeat tag argument of a tool, the user could use the functionality of multiple inputs (white pages) in workflows.
I would vote for the second proposal as it allows for building workflows with variable number of inputs (e.g. read mapping and combined SNP calling for a variable number of samples). Workflows with variable number of inputs have been brought up from time to time at several posts or meetings. Hence, solving this could be hitting 2 birds with one stone.
However, proposal 2 has the drawback that using repeat tag arguments outside of workflows is still a lot of manual work.
This could be circumvented by tiny workflows consisting only of the tool of interest (containing the repeat tag argument).
best regards, Jens