Plugin version 4.3 (and 3.2 for Free edition) is a brand new release, focused on performance improvements, changes related to WordPress 5.5, and few other general, under the hood improvements and some bug fixes.
From the early versions of the plugin, the plugin had a cache layer for in-memory caching of various things. But, over time, the complexity needed to handle a large number of rating items loaded, multiple rating methods, was not followed by the expanded cache support. This version changes that with more results cached and with the use of the preload object made to cache in advanced items from loops or list of items.
In some cases, the plugin runs 90% fewer SQL queries than before. for instance, the plugin dashboard contains a widget showing 10 latest votes. The previous version needed 71 SQL query to get all the data for the list. Now, the plugin runs 7 SQL queries. This is an extreme case, but, with most other use cases, you will see performance improvements. If you automatically add ratings into comments (Like This for instance), and you have a long list of comments, for each comment you need few queries. Now, open plugin Settings -> Ratings in Comments panel, and enable Preload option. After that, no matter how long the comments list is, the plugin will run a few queries in total.
New version includes some changes for WordPress 5.5 compatibility, including improvements to REST API addon and various other improvements and fixes.
Comment Form addon has been also updated, including few improvements and support for update cache and preload functionalities from the main plugin. GD Rating System Free edition has been updated with pretty much the same changes that Pro plugin version has received.
To see the list of all the changes, please check out the changelogs for: Comment Form Addon, GD Rating System Pro. If you find any issues, please, report them in the support forums for: Comment Form Addon, GD Rating System Pro.