The rising demand for UHD and 360°content has driven the creation of advanced compression tools with enhanced coding efficiency. Versatile Video Coding (VVC) has recently improved coding efficiency over previous standards, but introduces significantly higher computational complexity. To address this, this paper presents a novel intra-coding method for 360°video in Equirectangular Projection (ERP) format that reduces complexity with minimal impact on coding efficiency. It shows that the North, Equator, and South regions of ERP images exhibit distinct complexity and spatial characteristics. A region-based approach uses multiple Gradient Boosted Trees models for each region to determine if a partition type can be skipped. Additionally, an adaptive decision threshold scheme is introduced to optimise vertical partitioning in polar regions. The paper also presents an optimisation solution for the Complexity/BD-Rate loss trade-off parameters. Experimental results demonstrate a 50% complexity gain with only a 0.37% BD-Rate loss, outperforming current state-of-the-art methods.