As an alternative, you can use the ox-pandoc package. Pandoc itself has a command line option called --self-contained which will embed images in html.
To you use this for just the pandoc HTML5 exporter, by putting this in your .emacs:
(setq org-pandoc-options-for-html5 '((standalone . t) (self-contained . t)))
Also, you could have it for html4 instead/as ...
I would use
#+ATTR_LATEX: :width 10.6\textwidth
This is described here: https://orgmode.org/manual/Images-in-LaTeX-export.html
For specifying image ‘:width’, ‘:height’, and other ‘:options’, use this
#+ATTR_LATEX: :width 5cm :options angle=90
You might try customizing one or both of these image-dired options (the text is what you get with C-h v).
image-dired-thumb-relief - Size of button-like border around thumbnails.
image-dired-thumb-margin - Size of the margin around thumbnails. This is where you see the cursor.
There are many other image-dired options, some of which might also help you more ...
I have a solution that does 2 things:
Attempt to open any XML file in nXML mode, and this obviously needs to include SVG files.
If such a file is an SVG file, then define C-c C-c to image-mode.
For the first item, I use magic-mode-alist to select nxml-mode on some sequences at the beginning of the buffer: <?xml, some DOCTYPE line with XHTML, and <svg ...