Planning the restructuring of your data from Universal Analytics into GA4 should be a thoughtful process. But, the work should be in the thinking - the business objectives, the future-proofing, the data model - not in manual data extraction and review, or the literal tag migration.
With Intarsia, you can migrate a complex Google analytics tag in less than 60 seconds.
Invest your time in the planning and strategy, and let Intarsia handle the tag migration details. For more about how this works, see the UA to GA4 Tag Migration demo video (7 minutes). Or, just get started with the migration tool.