Custom data on Members

Per this forum post there (is/was) no way to retrieve custom data on User. Does this mean there is also no way to update custom data on a user?

https://api-docs.liquidplanner.com/discuss/6577ed8de203d5003138d3d4

If there is no way via API, is there a way to do it bulk in the web interface.

Use case here is that LP Legacy had the concept of a "Team" that a member was a part of.
"Portfolio Manager" doesn't appear to have this attribute natively so we are attempting to recreate it.

I do not want to individually update 200 different members to assign teams... We are still in testing phase with plans to go live with production later this month.