Unfortunately, your suggestion would require a lot of change, maybe even a rewrite of the plugin, which is why this is not on the roadmap for the moment.
As already discussed with @dukeja, this would be better implemented in an additional plugin.
First of all hanks for you reply and consideration. You are totaly right, i just wanted to take my shot to see if you were considering it.
Although after using the plugin for a few week now, I have a new request if I may. A watermark (rather a simple username scribing etc.) so when sharing the generated png, svg etc. files some ownership or at least original author is shown in auto generated content.
Thank you for the request. This feature is not planned at the moment. However, you could maybe modify the final image in a image or vector graphic program so that it suits your needs.
Since the result is an image there is no possibility to modify it using joplin. The only possibility is to create a new mindmap that include your modifications.
This plugin comes (unintentionally ?) with a very nice extra:
when you create a mindmap with the classic Freemind application, then select a node and copy it, next paste it into a Joplin note and click on the Markmap icon .... voilà ... the node with all siblings, children etc is presented correctly in the window that opens.
Any formatting is lost (font styles, colors, etc.) but that does not diminish the value of this plugin. Big thank-you to you, Daniel.
It would be really nice if the Joplin team could vet this plugin and vouch for its security.