Of course you can run half a CPU at home. With Ubuntu LXD, you can easily run actual, hardware 50% cpu time, or .5 priority container. Why wouldn't you be able to have complete control over what "microscale" tasks you run on your own hardware, and own OS, that you control?
On the contrary, vCPU a completely cloud-centric product oriented concept, intended to abstract away what CPU you're actually running on, and how fast. These abstracts make orchestration and availability easier, but I think the key is a stable, public internet access. If you get a static IP, I don't see what wonders this does for "microscale". In fact, you probably have 90% unused "microcapacity" on all the personal hardware that's often idling, that is a lot less micro than any cloud provider will give you for free.