Very minor suggestion, but would be helpful to those of us who set run.R as the custom build script in RStudio:

• would it be possible to have use_targets() add an R shebang to the top of run.R? (probably #!/usr/bin/env Rscript)
• ideally run.R would also be executable out of the box, but I understand if you don't want targets to handle file permissions.

I am aware of run.sh but prefer to run the pipeline in a standard process when using the RStudio build pane.