Allow to create sketch map for bigger area of interest

I'm working in some projects dealing with Maritime Spatial Planning, where some activities are organised both with experts and stakeholders to collect spatial explicit knowledge about marine activities or environmental issues in the sea for planning or scenario creation.
In those cases, it would be useful to create sketch maps for very large areas of interest, e.g. the Adriatic Sea or event the whole Mediterranean Sea. Currently, the web interface allows to create a map only till a certain zoom level. Is there a reason for that or would it be possible to "unblock" this constraint?
In case this is not possible, can you suggest where to look in the code to create an instance of the tool that allows this?
Thank you for your great work!