I have a custom gauge set of String Joy nickel rounds on my MIJ Squier P. They're on their website, just scroll about halfway down this page to find the medium scale options. I've had mine for a while and was initially impressed with the tone, but they did seem to become dull a little sooner than my previous D'Addarios. I agree with @michael_t, they are on the stiff side of the spectrum, so they may not be what you're looking for.
I can't find these medium scale strings on the Dunlop or Fret Nation websites. I must be missing something, but I can't figure out what. @gruvit, would you mind posting a link for these?
I emailed Dunlop and they directed me to Fret Nation. They have kind of a goofy messaging system (no regular email address) that I think you have to create an account to use. They don’t have the medium scale, medium gauge listed on the site but if you message them they’ll send an invoice for you to purchase if you say how many packs you’re looking to buy.