Hello, That could indeed be problematic in subtle ways. The two versions store their preferences / recent files / libraries and all the other long-term-persisted files in the same spot.
I do understand the caution. Although 2025.1 is a stable update and I can’t say that there’s bugs I know of that would be problematic for you, upgrading your tools in the middle of a project, I understand the hesitation.
One thing you could do is use the beta: See the future of Sketch! Download the latest Beta · Sketch. This version is really separated from the official Sketch variant, and stores its libraries, defaults etc in a separate location guaranteeing that separation you are looking for