I have clip ons with stock rearsets
Works OK
Agreed, it works OK (but was not great, for me at least).
I ran my Cyclecat clipons with the stock rearsets for a season before changing them out for a set of Rizoma rearsets. I have found that having the pegs slightly higher and further back is a good match with the lower clipon bars. The stock pegs were a bit too far forward and low and with the lower bars I was doubled over at a kind of awkward angle. The Rizomas corrected that with the more aggressive riding position.
Whether you'll find the stock rearsets comfy with lower bars will probably depend on a number of things: how tall you are / how long your reach is / how low the clipons are / how long your legs are / how tolerant you are of pressure on your wrists / etc.
Sorry, no experience with the Monsterparts pegs.
HTH