IoT eSIM rollouts based on the GSMA SGP.32 specification promise flexibility and vendor independence, but real-world deployments often reveal hidden technical and commercial constraints. Drawing on hands-on experience with large-scale implementations, this article unpacks the less-visible complexities of the IoT eSIM ecosystem, highlights common lock-in traps, and outlines the critical questions enterprises and MVNOs should ask vendors before committing to an SGP.32 deployment.