If you do not select “infinite canvas” but instead set fixed dimensions, and then choose “Fit to Page”, it will auto-size for you.  I do not know if that solves the problem you are describing, but it is worth a try!

Hi ​@charlessilva, thanks for your post! 

Unfortunately, custom spacing with the default mind map template is not currently supported in Lucid. However, you can use any of these templates (Simple mind map, Sticky note mind map, Concept map template) which all allow for customized spacing between ideas.

We are continuously looking for ways to improve our products and your input is the most effective way to achieve that goal. You can post new ideas in the Lucid Community and these ideas will be shared with our Product Development team for consideration. Before sharing your idea, please explore our community to find existing suggestions. Upvote or comment to voice your support, as all feedback is channeled through our community.

For details on how feedback submissions are collected and considered, check out this Community post. 

Cheers!