The toolset keeps a list of the projects (actually: mini-XML files pointing to the directory where the projects are located) in tomcattools/webapps/editor/config/projects (which is not totally beautifuly, but that's a different story...).
When using the toolset via SpringBoot (new from 20220425 on), then: where are these project files?
THe editor checks if it is running in exploded mode (like in Tomcat scenarios: the .war file is exploded into the webapps directory). If you it uses the optional servlet-API to access the directory directly.
If this optional API is not existing (because the servlet engine does directly work on the .war file) then the editor uses the general temp-directory of the user: