There are software to keep your PC awake when it’s in use (by CPU, network, file system) automatically. See https://stellawake.com/

I don’t recommend scanning slides and negatives with flatbed scanners. The results will be disappointing, as explained in this article: https://autosplitter.com/slides-to-digital/

I don’t know guys... I like the print version better than the negative version. It’s more vivid and higher contrast... Yeah sometimes too much contrast but the negative doesn’t look better overall. Definitely might be worth a try. Or use a photo scanning software with automati color correction, like this: