Having to align the pointer and click dozens of check boxes is multi-select tracks for playlists or deletion is slow and frustrating. Please allow us to use industry standard multiple selection, and don’t force us to scroll back to the top of potentially hundreds of imported MP3 files to get to the “Add To Playlist” button.
The above is for the computer app. As for the mobile version, multiple selection via checkboxes would be a blessing.
I know computer shift+click has been escalated to devs a number of times before, but this would make a big impact.