Rolling Knife Sharpener, Diamond & Ceramic Disc, 15° & 20° Magnetic Angle, Fast & Safe for Any Hardness, Sharpening Kit for Kitchen & Pocket Knives, Razor-Sharp Edge, Leather Strop, Classic Kit

These types of sharpeners work really well and while they aren’t the smallest thing to carry, they also aren’t huge. Two roughly “fist-sized” pieces to pack: https://www.amazon.com/Sharpener-Rolling-Sharpeners-Hardness-Magnetic/dp/B0CSJTK8KL/spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfbXRm&psc=1