Sun shadows now can affect road temperature (can be enabled in general settings for offline or in a server config for an online race). Wouldn’t be a big difference on most tracks, but some tracks, such as Monza, can be fully shadowed for a half and lit by sun for another half, so it might be a noticeable difference.
Triple screen mode now supports Extra FX (although in a limited way; TAA, for example, not quite working yet; and it would still be a major performance hit so you need to enable it separately in Extra FX settings).
Anticheat part has been improved, now hopefully it should be a bit trickier to be able to hack into CSP itself.
Mesh-based masking culling: tracks now can prepare a low-poly mesh that can be used for hiding things behind it without all the complications of arranging vertical walls with a config.
A lot of fixes of all sorts, like improved rendering for new trees, fixes for ExtraFX emissive, fixes for advanced culling, a bunch of performance and stability improvements, better Wine support for Linux users. Ah, and Lua GIF player now supports animated WEBP as well (along with other improvements for Lua too).