Hi Ben,

It is possible to search by custom fields using the Salesforce integration by adding a new "Account" object in your Objects list.
When adding a new Account object, it will create the Account object followed by a random 4-digit identifier to differentiate between your custom Account object and the default Account Object.
In your custom Account object, you can add the Fields of interest, and you will then be able to search this Account object by any of the fields.

As an example, I created a new Account object for which I want to search by SLA.

As you can see, in my list of Actions I can Search the Account by a "A searchable field in Account"

In my workflow, I can then search my accounts by SLA.



I hope this helps!