Such an awesome tool, though, could you add the option to add icons with / instead of text? Would be great.

That is a good offer. It is a very simple function.
However, it takes a lot of effort to provide it in the tool. It is difficult to change the tool.
So, attach a script that provides the function. Edit the 'icon_index_list' hash, and edit the command list with the list of icons you want.
Thank you.

Have you ever thought of making it for other RPG Makers? Even if it was paid for, it would be paid for.