It's no wonder you were confused when posters start talking about SUT's for 40db phono stages when yours is 53db.
Its also unfortunate when folk do a 300 word diatribe on their own system that bears no similarities to yours.
The bottom line is :
Soundsmith for example for their 1.1mv output cartridge recommend a 53-54db phono.
The Grado at 1.omv should be about right for your 53db phono.
The gain difference you are experiencing as @lewm said with line is that many digital systems have quite a high output.
The suggestion that the 2.5mv Benz will provide more headroom is completely wrong. By putting a higher output into your phono you will have less headroom in the phono section.
I have a friend who had no trouble running the same medium output Benz into a 55db Conrad Johnson phono.
The difference comes down to noise floor, the lower the output the higher you have to turn the volume up then the higher the noise floor.
Cartridges around that 1.0mv include Grado, Soundsmith, EMT.
Also Van den Hul and Benz both do cartridges around 0.7 that should still work, given that your power amps are very sensitive and you have plenty of overall gain in your system. It just comes back to what is an acceptable noise floor with the VDH and Benz vs the slightly higher output other Grado, Soundsmith, EMT.
Either the Grado or Soundsmith medium output would be the simplest option because they are both optimum at 47k - which suits your phono. Both great cartridges.