Is there any reason why I should use
rewrite_rules_array instead of
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.