Exporting content larger approx. 5mb causes the server to restart

To reproduce:

Go to: https://demoauthor.magnolia-cms.com/.magnolia/admincentral#app:dam:jcrBrowser;/travel-demo::
and export travel-demo.

Export will not start and the connection to the server will be lost after some time.

Dev notes:

• Same happens when exporting through JCR Tools / Exporter on our public demo
• Export is not broken in general. Exporting small files is still possible. In the test env with 4gb ram, java 13, tomcat 9 exporting 2 png with each 3mb is not possible, 5 jpgs with each 200kb is possible
• Tested H2 and MySQL database underlying, same result, no export but connection lost to server.
• Same behaviour with Tomcat 8.5.58

The problem may be here:

info.magnolia.ui.contentapp.action.CommandAction#executeSynchronously

This takes a long time to execute.