Use $wpdb for realtime actions

[k1sul1]

TL;DR Me using PDO has the cost of opening a new database connection. Every time a request goes to PHP and this plugin, 2 connections are opened. It takes a bit of time and resources to open one, using $wpdb will get rid of the overhead at the cost of me ripping my hair off.

In bulk generation it doesn't really matter, but for requests to the endpoint it does. Unless you cache heavily, which you should, but still...