I am actually a CTO turned CEO of a startup, and somehow couldn't help to get my hand dirty but couldn't do it in my company right now, you know the whole "trust your CTO" thing.
Randomly visiting freelancer and stumbled upon your post
I have hundreds of gigabytes of tables that need to be moved around, converted, repaired all the time on mysql and mariadb. and yes, different ways of doing it can cost you days compare to hour. I couldn't assure the 3 days since I have no idea how the tables is structured (since table types and indexes can be a major problem) and also what you mean by "convert mysql tables to woocommerce mysql tables" since both are mysql tables.
I don't have any experience in woocommerce, but i guess that you'd really like to do is migrate your table to new table with different schema. You can contact me over telegram at +6281573207632. Even if you don't hire me, I'll be happy to help give some clue on what might happen to your script and tables