Category (the category and its parents, top first, as [{"title": …, "alias": …}]; an older Apps/Dev alias path is still read), Access (the access level's title), Level (the level's name), Add groups, Remove groups, Purchase type and License policy. Saving a product writes its custom data whole, so keys PaddleSubs no longer uses are dropped.

Not verified: whether Paddle replaces a product's custom data on update or merges it with the keys already there. If it merges, old keys stay.

Billing type, Period frequency, Period interval and Fixed end date: how long a one-time price's access lasts.

Group key, Ordering, Scope, From, To, Same category, Eligible after expiration and Number of products: the rules of relation and bundle discounts. A category scope uses the same structure as a product's Category.

Access subscriptions on transactions saved from the administrator, which Sync from Paddle restores; and paddlesubs_license_id on checkouts started from a renewal link.