interactive book

Hi folks,

I'm working on a project to bring a "taditional" course with a workbook online to a custom Moodle LMS.  The approximate format of the course is: Watch a video, have a discussion, write down reflections in a workbook.  We want to host the video on our Moodle course, provide a discussion forum, and then provide some sort of virtual workbook.

• https://h5p.test.schulcloud-thueringen.de/node/1092410
• https://github.com/h5p/h5p-interactive-book/pull/59
• I've tested the PR above hoping to benefit from Interactive Book saving the results when you navigate away and resume from where you left. 
• Via plugin mod_hvp it works, I can even log off and log in again and it returns with proper state, but I got an error while trying to submit.
• Via Moodle core h5pactivity, it doesn't work, if I change to another activity and c

I'm trying to add images in an interactive book. Some of the images are decorative - not alt text required - however I'm forced to add alt text for them.

If I leave the fields blank then H5P inserts the alt text "new image".

Its good to prompt people to add alt text but there should be a check box to allow for decorative images.