In a comment to a post on my paper, Andrea Cau suggested I use his reconstruction of Spinosaurus to run my analysis and compare it to the one I used in my paper (the reconstruction from Dal Sasso et al., 2005).
So here is the result. The plot above shows all the mechanical advantages from my 41 taxa as grey dots. The black line is the Spinosaurus from Dal Sasso et al. (2005) while the red line is Andrea's reconstruction. There is an obvious difference, with Andrea's showing higher mechanical advantages overall. However, in the whole scheme of things, the difference is quite small. There isn't a drastic difference in the profile either. So all in all, this is good news, both to me and to those that reconstruct skulls.