Some of the most beautiful and creative lace patterns violate this rule slightly here and there, relying on the natural stretchiness and flexibility of the fabric to make up the difference. This pattern goes even farther: it increases 50% faster than it ought to -- 24 increases every fourth round, where the rules allow only 16 increases.
The only thing that allows this pattern to work is the fact that it is knitted in a thread that is very fine relative to the size of the needles. If you cannot find thread fine enough to work this pattern as specified, you may start from the Feather and Fan Cloth pattern, which has 16 repeats of the pattern, rather than 24, and continue following the chart for Oma's Lace beginning with Round 2a.
This pattern also works in #30 cotton on size 4 needles (3.5mm). Presumably, #50 on 2's and #40 on 3's would work. #60 thread is about the same thickness as sewing threads. I've never seen anything that fine in a standard crafts store. Thread this fine and finer, as well as the needles to work it with, are sold by Patternworks and Lacis, and probably other suppliers.
I have recently (okay, yesterday) discovered a very similar pattern in a classic collection of patterns, The Knitted Lace Patterns of Christine Duchrow, vol. III, which I just bought from the Needle Arts Book Shoppe. Pattern #57(4), on page 11, has a slightly different center portion and -- perhaps you guessed it! -- 16 repeats in the feather-and-fan portion.
x2 = 2 times, etc.
1a: (k1, yo) x2; k2tog x3; yo, k1, yo
1b: (k1, yo) x2; k1, k2tog x3; yo, k1, yo
1c: (k1, yo) x2; k1, k2tog x3, k1; yo, k1, yo
2a: (k1, yo) x3; k2tog x4; yo, k1, yo
2b: (k1, yo) x3; k1, k2tog x4; yo, k1, yo
2c: (k1, yo) x3; k1, k2tog x4, k1; yo, k1, yo
3a: (k1, yo) x3; k2tog x5; (yo, k1) x2, yo
3b: (k1, yo) x3; k1, k2tog x5; (yo, k1) x2, yo
3c: (k1, yo) x3; k1, k2tog x5, k1; (yo, k1) x2, yo
4a: (k1, yo) x4; k2tog x6; (yo, k1) x2, yo
4b: (k1, yo) x4; k1, k2tog x6; (yo, k1) x2, yo
4c: (k1, yo) x4; k1, k2tog x6, k1; (yo, k1) x2, yo
5a: (k1, yo) x4; k2tog x7; (yo, k1) x3, yo
5b: (k1, yo) x4; k1, k2tog x7; (yo, k1) x3, yo
5c: (k1, yo) x4; k1, k2tog x7, k1; (yo, k1) x3, yo
6a: (k1, yo) x5; k2tog x8; (yo, k1) x3, yo
6b: (k1, yo) x5; k1, k2tog x8; (yo, k1) x3, yo
6c: (k1, yo) x5; k1, k2tog x8, k1; (yo, k1) x3, yo
7a: (k1, yo) x5; k2tog x9; (yo, k1) x4, yo
7b: (k1, yo) x5; k1, k2tog x9; (yo, k1) x4, yo
7c: (k1, yo) x5; k1, k2tog x9, k1; (yo, k1) x4, yo
8a: (k1, yo) x6; k2tog x10; (yo, k1) x4, yo
8b: (k1, yo) x6; k1, k2tog x10; (yo, k1) x4, yo
8c: (k1, yo) x6; k1, k2tog x10, k1; (yo, k1) x4, yo
9a: (k1, yo) x6; k2tog x11; (yo, k1) x5, yo
9b: (k1, yo) x6; k1, k2tog x11; (yo, k1) x5, yo
9c: (k1, yo) x6; k1, k2tog x11, k1; (yo, k1) x5, yo