Cartridge break in

Agree with Rodman and Mosin. With regard to Pops' experience, I've experienced both. Some cartridges change wildly in the first 25-100 hours, including basic changes in character - particularly at the frequency extremes. Others barely change at all.

Some suggestions:

Make sure you're cleaning the stylus effectively (ie, Magic Eraser + brushing) after every side

Make sure your LPs are truly clean

Check with VPI to see if they recommend additional headshell weight for the Kleos (they can provide)

Try increasing VTF in .01-.03g increments, listen for some taming of high frequencies

Try lowering arm height by TINY amounts, listen for closer integration of HF harmonics with their lower frequency fundamental

Try changing the phono input impedance, which is adjustable on your Musical Surroundings.

I'm unfamiliar with the Musical Surroundings SuperNova, but in principle I concur with Downunder. An inadequate phono stage can distort the richly detailed but very low level signals produced by really good LOMCs.

There's reasonable debate over the "best" order for upgrading turntable vs. tonearm vs. phono stage. IME, upgrading any of these yields positive results.

OTOH, there's almost no debate (among those with experience) that ALL THREE must be up to snuff before undertaking a major cartridge upgrade.

Disproportionate cartridge upgrades are often disappointing, either because a high end cartridge reveals weaknesses in its support system (TT and arm) or because the phono stage can't cope with the depth of detail.

From my own components... my $8K LOMC sings like a goddess on my main rig and phono stage. She does all the audiophile things but in a coordinated way that makes ravishing, lifelike music. However, she can sound miserable on an entry level rig or feeding a low quality phono. If I'd bought this cartridge before having a suitable TT, arm and phono I might not have been happy.

OTOH, I've tried several inexpensive MMs in my main system and most play way above themselves. A $275 MM can fool people into thinking that it's a $1-2K cartridge.

TT, tonearm and phono stage first. Cartridge upgrades should wait.