Is there any reason why I should use rewrite_rules_array instead of generate_rewrite_rules?
generate_rewrite_rules works out of the box, but I couldn’t get rewrite_rules_array to work.
And I am told that any array actions [when adding custom rewrite rules] should be done via rewrite_rules_array and the rest of *_rewrite_rule filters (e.g. add_rewrite_rule). It’s unclear why.
This is possibly a matter of opinion, but I would say – neither. If you’re simply adding new rules, use
add_rewrite_rulehooked to theinitaction.