Updating Single Select Fields From Updated Linked Records

If I'm understanding correctly, there's 2 tables. A user table and a transaction table where the USER singleselect field is.

You can put the single select field in the USER table instead, and look up the single select field in the transaction table. That way it is always up to date!

Yes, I have a USERS table and a PRIMARY table that includes the linked field of users and all related data. The reason I included all those additional user fields is because they were attempts at trying to automate the creation and population of the Single Select Field. The only reason for going through this hassle is because Single Select Fields when displayed in my online portal are more visually distinct than just plain text. I hope this clarifies things! 

USERS (TABLE 1)

PRIMARY (TABLE 2)

What difficulties did you face creating an automation that'll paste the value of the linked field into the single select field?  Not sure what the resulting colors would be so that might be a problem

Highly recommend trying Sally's suggestion about moving the select field to the User's table and using a lookup field first though

So the tables would look something like this?

USERS (TABLE 1)

PRIMARY (TABLE 2)

Yeap