Most users assume the only risk is "it might not work." That is dangerously naive. Here is what actually happens when you install a V-Ray 3.4 repack.
Released in early 2017, V-Ray 3.4 for SketchUp was a paradigm shift. Before version 3.4, V-Ray was notoriously complex. Version 3.4 introduced:
Chaos provides a 30-day full-feature trial of the latest V-Ray for SketchUp. If you need 3.4 specifically, their support team will even provide legacy installers upon request.
Full access to all modern V-Ray features, including GPU rendering, Chaos Cosmos asset library, and V-Ray Vision.
Using an unofficial repack changes how the software interacts with your operating system and hardware. Resource Efficiency
For a safe, secure, and fully functional 3D rendering experience, designers should avoid obsolete repacks and utilize the official, up-to-date versions of V-Ray. The Problem with V-Ray 3.4 Repacks
Offers both CPU and GPU rendering acceleration to maximize hardware efficiency.
If budget is the primary constraint, several free or open-source renderers integrate smoothly with SketchUp:
Automatically removes noise, cutting render times by up to 50%.