For both Hubspot and Salesforce integrations, Clay fetches all fields in a single step for any given record, and then stores those values for use in later columns. You can update multiple fields in a single step as well.
Where you might run into trouble is trying to build every necessary CRM enrichment into a single table or flow. Typically how I structure enrichments are as grouped pipelines by topic or task - for example phone number enrichments, ICP scoring, etc. Then I filter records into those workbooks when they meet the criteria for inclusion and enrich the fields necessary for that set of tasks.
