API - Working with assets assigned to a user

We are doing a lot of work with assets right now and I have a major pain point I wanted to see if anyone has a good solution for.

I am not able to view or act on assets assigned to a user in the WFA without doing an API call for the user to get the user ID, then do another API call for asset lookup to get the display_ids for the assets assigned to them. Am I missing something?

It would be so much easier to have an option to use include_assets=true to return the assets assigned to that user, all we would need it to return is the display_id for each asset assigned to them.

Something like this:

I know I can setup a custom objects table to lookup the User and have it return the user id and all the asset display_ids assigned to them, but we have over 3000 CIs in our CMDB. I don’t want to have to manage a Custom Objects table that big.

Anyone have a way to deal with this conundrum?