I did a similar tire swap on my platypus.
I had been running Rene Herse 55mm knobbies in endurance casing.
I recall Jan saying they have similar rolling resistance to the standard casing and I have zero complaints about them.
I just wanted to try a bit smaller tire.
I went with the Ultradynamico Cava JFF in 48mm
The bike definitely steers a little quicker, not a lot but it does feel like it rolls smoother.
I’m still nursing a torn hamstring but I rode for about 3 hours which is at least an hour longer than I have been riding.
I have another bike that runs 42mm so the 48s were a good choice.
We are living in good times when it comes to tire choices.
Ray