Give the scene a job
An object being able to spin does not make it meaningful. Decide what movement explains: product structure, transformation or relationships between parts. Do not make people wait for animation before reading. Progress, back navigation and links should retain normal browser behavior. The visual should support the explanation of what the company does.
Every device does not need the same scene
Design a static composition for small screens, data saving and reduced motion. It should communicate the same idea rather than merely show a loading indicator. Load the rendering engine when it will actually be used. Avoid delaying fonts, the main heading and the initial visual with unrelated downloads; this improves powerful devices too.
Pause a scene that cannot be seen
Pause rendering when the tab is hidden or the visual is off screen. Apply a measured pixel-ratio cap instead of always using the device maximum. Reuse geometry and textures and release GPU resources during navigation. The aim extends beyond smaller downloads to reducing the CPU, battery and heat cost of continuous rendering.
Lab measurements and actual use differ
Controlled tests help compare design decisions. Actual visitors have different networks, devices and interactions. Consider initial content, completion of the main visual, layout stability and interaction response together. One high score is not evidence for the whole experience. Plan live measurements with anonymity and consent choices in mind.