The attachments do become part of the agenda data, and so will be in iCloud if you have sync turned on. This takes up space in iCloud (or Dropbox, if you are using that).
The only limit is your iCloud/Dropbox account data. I think the current free tier is about 5GB for iCloud, which is not that much. For about $10 a year you can grow that quite a bit. But that is all up to you.
Thank you, I understand how it works now
I have another question though, is there a way to edit or modify this files attached to a note? Like a pages document for example
There is no direct way yet. We would like to allow that in future.
For now, you would have to save the attached file to another app, edit it there, and then import it again as a new file, deleting the old one. That is how you would have to do it.
fwiw I really like how Agenda currently works. I attach files to serve as an archive, and like that I don’t have to worry about accidentally modifying them when I open them in another program. If I need to make changes, I save a copy and re-add it to Agenda – which means I can keep a running archive of multiple versions if need be. So hopefully if you add this, we’ll have the option to open editable version or something like that, but still maintain current behavior.
Yes. You will get a preview of it with the upcoming pencil support. We have set that up so you can edit. You explicitly tap an “Edit” button, so it is unlikely you would accidentally edit the file.