You can raise GitHub issues against the Zowe Explorer repository. It is suggested that you use either the bug or feature request.
Please provide as much of the information listed on Troubleshooting Zowe Explorer as is reasonable. Anyone working on the issue might need to request this and other information if it is not supplied initially. A description of the error and how it can be reproduced is the most important information.
Feature requests are just as important to the Zowe project as bug reports. Feature requests should contain clearly formulated ideas that can improve user experience.