As the great majority of cpu's have multiple cores now days, are there any plans to allow assigning multiple cpu cores to completing a work unit/task?

The best multicore processing possible from the point of view of computational efficiency is X independent tasks that are processed independently in their own single-threaded process. As it is now(and from the start) implemented in SiDock and many(most of) other BOINC projects.
Parallelism is provided at the data level and can be efficiently scaled to any available number of cores/threads without additional efforts.

No multi-threaded application can surpass it, at best it only can come pretty close to it.

The only significant drawback of the "X independent tasks running on each of the CPU cores" approach vs MP-app is a much higher consumption of RAM.
But since specifically in SiDock the RAM usage is quite low (usually under 200 MB per running process), then SiDock does not really need any MP applications at all.

And all the available resources/time of developers is much better and more useful instead, to let them complete the development of the GPU application of CmDock. Which has been in the works for more than two years now. And which they promise to "finish soon" (last such "soon" was about 8 months ago), but so far they have not been able to finish it.

The best multicore processing possible from the point of view of computational efficiency is X independent tasks that are processed independently in their own single-threaded process. As it is now(and from the start) implemented in SiDock and many(most of) other BOINC projects.
Parallelism is provided at the data level and can be efficiently scaled to any available number of cores/threads without additional efforts.

No multi-threaded application can surpass it, at best it only can come pretty close to it.

The only significant drawback of the "X independent tasks running on each of the CPU cores" approach vs MP-app is a much higher consumption of RAM.
But since specifically in SiDock the RAM usage is quite low (usually under 200 MB per running process), then SiDock does not really need any MP applications at all.

And all the available resources/time of developers is much better and more useful instead, to let them complete the development of the GPU application of CmDock. Which has been in the works for more than two years now. And which they promise to "finish soon" (last such "soon" was about 8 months ago), but so far they have not been able to finish it.

There are several people that have helped projects in the past tweak the gpu app making it faster, I wonder if one of them might be able to get it over the finish line if they just asked? Now to be fair the volunteers so far have only worked on the Linux Nvidia apps limiting their helpfulness, but something is better than nothing. Apparently the Windows gpu apps are a bear.