i have always knit hats on 29 to 32 inch circ’s.
this size is too small for a proper ‘magic loop’ and too big (even for my bowling ball sized head.
but you can do a sort of half magic loop…
and eventually work down to real magic loop (or do the opposite, start the hat at crown using a circ in a magic loop, and as more and more stitches get added, change to half magic loop.
some knitters find this uncomfortable… but i love not having to change needles (before i had a huge selection of circs, i used to knit on DPN (–sometimes using 6, or 7 not the more standard 3 (4) or 4(5)…
i used to lose DPN’s… so i have several ‘sets’ that have 2 pink (aluminum) ones, 2 blue and 2 silver… (a set of 6 in one size)
they started out as 3 sets of 4 needle…and now of 12 origninal needles, all i have are 6… (i have been knitting a long time!)