An "upgrade" is nebulous because the cartridge was designed as a complex interplay between a very specific set of parts. A ruby/sapphire rod is a lot heavier than boron; I would avoid that for sure. The exact stylus cut is probably far less impactful than nearly DOUBLING the specific gravity of the cantilever material, and both Gygers are very good. As others pointed out, retipping on the existing boron rod might be a good way to go, but I don’t know if or how that might compromises the mount/bond (which IS important). Lyras usually use a very clean looking interface mount and I doubt that’s what you’ll get unless you do an exchange with Lyra themselves.
