Magneto is a tape head delay emulation with some extra looper/echo/reverb fx functionality.
Mimeophon despite the lack of dual pitch shifting is more akin algorithmically and very much so sound-wise to a vintage digital rack delay like an eventide or lexicon, but with extensive cv control.
Personally I think Magneto is a good emulation (sounds more familiar mono too, I think, since that’s generally how it was done back in the day), but I prefer the sound and control options of the Mimeophon, which I find more complementary to modular than a tape emulation.
But If I were running vocals and more hifi recorded signals through modular, I would try the Magneto first.