Problem:

could we add to the image shortcode something for a higher version, but low size?

Solution:

You can try custom CSS codes, like this:

https://toolset.com/forums/topic/custom-css-codes-issue-3/#post-2235693

Relevant Documentation:

Problem:
The user was still able to save new posts even if the required fields were not entered.

Solution:
We have found the cause of the issue and produced a patch that you can apply on your website. Please download the following zip https://toolset.com/patches/validation.js.zip
Then extract the file "validation.js" file to "types/vendor/toolset/toolset-common/toolset-forms/js/"

You will need to purge the browser cache to make sure it will use this patched file.

If this patch did not land on the next release, you will need to apply it again, manually.