1) Is it possible to save all additional ACF data fields at custom database table? For example create at WP database new table “auto_engine” and there save all needed engines with their specs? (So not save them as metakey.)
2) If yes, then is it possible to create different tables for different fields or different posts/products categories?
3) If yes, then is it possible to later add new fields and re-arrange database table columns?
4) And connect those fields to needed posts?