Hi @Karel Husa 
Thanks for sharing your thoughts! We are always looking for ways to improve our product, and your idea of the Mind Maps having more variables could certainly become a great addition to our product!

Would you please be so kind to head over to our Community and submit your idea to our Wish List? By adding your idea, you’ll help us collect all the feedback in one place and make sure it is reviewed by our product teams.

To answer your question, the GIF demonstrates how you can extend existing mind-map nodes and create custom blocks.

As for custom templates, the following article perfectly describes how to create, share and use them: Custom templates

We do hope to see your idea on the Wish List soon! Thank you for making Miro better!

@Nick_Miro ,

the idea of rich text inside mindmap blocks has been already raised by @Kai Strandskov here.

Thanks for the illustration how to connect blocks with the mindmap nodes, it is helpful, however if you change the mindmap (e.g., add nodes) you need to move the linked blocks manually. 

Mindmap nodes with a label and rich content which could be shown/hidden seems to me still the best option.

Best regards,

Karel