Purely hypothetical: what would happen if you crossed a show homer with a racing homer?
Would you get a bird that looks good AND races? Or the worst of both?
Generally you’d get a mediocre bird for both purposes.
Show homers have been selected away from racing traits for decades. The physical traits breeders want (body shape, head, stance) often work against racing performance.
First cross might still race okay. But you’d be diluting racing genetics with non-performance traits.
If you want pretty birds that race, select within racing lines for appearance. Don’t cross purposes.