How to Mass Assign Read-only goal with weight?

Summary

In the recent releases, we are not able to mass assign a read-only(Allow workers to update key attributes is No) goal with specific weight

Content

We are on 20C, will be on 20D when the goals and performance cycle starts for us. Until 19X we were able to mass assign a Goal with "Allow Workers to Update Key attributes" set to No and with 10% Goal weight using the previous Mass assign functionality. In recent releases, 20X, we are not able to do the same. We can mass assign with weight but the flag for "Allow workers to update key attributes" is not available.