I think everything I tried from that set so far worked well with fountain pens, though I did like some more than others. My favorite so far was probably the Mnemosyne notebook. The Rhodia webnotebook (not in the sample pack) is fantastic too.
For physics, math, general writing, I'm using Roaring Springs buff colored engineering pads (#15 paper type). Fairly fountain-pen friendly, though not as good as the papers in the above sampler set. I haven't found fountain pen paper with an engineering grid yet though, so it's the best compromise so far. The green 200 page pads are actually pretty good for fountain pens last I tried them, however the sheets were too thin for my taste and tended to eventually curl up where my forearm rested on them. Worth mentioning that the last time I bought these pads was back in 2020 when I got a 24 pack box that's still going strong, so it's possible paper quality has changed since then.
For reference, the pen I'm using is a Karas INK V2 with a EF Bock nib. Ink is Noodler's Black.