Many projects nowadays want to have a (Contributors License Agreement) CLA signed for safeguarding the project and the contributors from patent, ownership or other legal issues. I request gitlab to provide native support for CLAs. Once such a system is in place, project owners can create a CLA (which could be added as a file, as part of the sources, CLA.md), contributors could accept/sign it digitally.
Any PRs opened will not be merged until the contributors agree to the CLA. This can become an automated system (somewhat like CI testing before merging).
The CLA could be on a per-project basis. A list of people who have signed the CLA could be recorded as part of the metadata so that the subsequent PRs from them need not be shown the CLA dialogs again.
Some examples of CLA systems in action are: https://cla-assistant.io/ and http://clahub.com/
Instead of relying on these external systems, I want to use only gitlab for all my FOSS project needs. This will be an excellent value addition.