Considering it’s set in the future and modern studies into rapid wound healing (like this one www.sciencedaily.com/releases/…/230418011121.htm this one www.nature.com/articles/s41598-023-50009-3 and this www.ncbi.nlm.nih.gov/pmc/articles/PMC7463929/) it’s fair to say that stimpak like tech is not unrealistic in its nature. It actually follows research trends of the 1990s.

experience time dilation at my own whim

Perceived time dilation.

And Jet is pretty much a variant of meth.