for me, it was even worth to replace my MM for a another MM (Moog Mother 32), which is a one OSC Mono Synth. i don’t regret my decision so far ;). just a little bit, i miss the sound possibillities of the Monomachine MK1, but not the crappy encoders that robbed me the fun at the end.
I don’t think that this would be an upgrade at all:
The SuperWave engine uses 8 oscillators per voice, the Korg Monologue in comparison offers 2.
If you feel attracted to having real analog oscillators and nice sounding analog filters, then yes, you will get them with the Monologue, but as an substitute for something as powerful as the SuperWave engine: no!