Hi Max,
I'm afraid we don't support editing of Metadata via the UI, mostly because we didn't want users to overwrite existing metadata (with no record of what was changed), but also because it's not been a high priority to add this functionality before now.
However, one advantage the scripts have is that you can customise the type of data that you request from your users and you also have the ability to batch process many images at once (or even a whole Dataset of Images).
NB: In my example script above, I created a separate Instrument etc for every image, whereas it is also possible to create a single Instrument and link it to each image.
Regards,
Will.