My Sp01 has one of the CZC versions. Without that tapered end i'm not sure you'd be able to get it into the slide with the barrel in place.
Fitting the factory plastic one, you have to curve it some to get it in there.
It isn't quite as tight as the fit of the factory s2 though.
Here's the s2 compared to the aftermarked sp01. Sp01 is shorter, so not cross-compatible. Just showing the images for reference. Factory has the same tapered tip, although less so.


You might be able to get away with a shadow 2 version, cut down. You could contour the tip as little as possible while still getting it to fit. I imagine you'd still need the taper some though to get it in. My sp01 is a relatively tight fit with the barrel in place.
I did attempt to fit the s2 rod in the sp01 and i was not able to get it in there. Too much intereference in the tip when the rear is not able to get past the peanut area of the barrel. If it was shortened it might work.