add/update the lag through client code
please add the ability to add a lag to a tasklink. This is not available and not possible in PSI for project online. We have many times fallen short of a project online solution because this is missing.
Others have had the same issue for years as well - https://social.msdn.microsoft.com/Forums/en-US/6386b55a-4a6c-4f13-b778-beb4faf8fc20/setting-lead-lag-on-a-predecessor-using-csom?forum=project2010custprog
Roy Gilboa commented
Extremely bizzare that the lag information is missing. You cannot even retrieve it (thus tyou cannot update it) from code.