Hi! Thanks for the appreciation!
I highly doubt that anyone tried to apply supercompilation to Datalog, since supercompilation is mostly known in the area of functional programming. I did not research any specialization techniques for Datalog at all, and I couldn't find any papers on the topic right away. I'll provide a couple of fundamental works on specialization of logic programming, maybe they were or can be applied to Datalog.
There is a general framework of fold/unfold transformations for logic programs which can be used for specialization: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.32.3295&rep=rep1&type=pdf
Partial evaluation specifically for logic programming (also known as partial deduction) is described here: https://www.sciencedirect.com/science/article/pii/074310669190027M
The link between supercompilation and partial deduction is described in this paper: https://link.springer.com/chapter/10.1007/3-540-58402-1_13