Lookup of Lookup fields appear as JSON and cannot be used in many functions

Describe the problem

You cannot sum a lookup of a lookup, or perform any aggregate functions on them. This is because under the hood a lookup of a lookup is you looking up a JSON array and we don't yet have an easy way of SUMing etc these values.

Steps to reproduce

1. Create a lookup of a lookup field
2. Try to use this field in a formula

Actual result

You are shown json values.

Expected result

The values should just be the looked up values as expected.