those are some good strategies veehelm, but i'm referring to characters who's u-air/u-smash will outprioritize yoshi's down b. you're right, it is a character dependent issue. basically, playing battleground against a chracter with a good u-air/u-smash i find pretty difficult. down b to the ledge is most def the safest thing to do, or just air dodging their u-air. but with the disjointed hitboxes of some characters air dodging isn't really an option (lucas). while yoshi is indeed strong in the air, his d-air is atrocious as far as priority and down b used too often becomes predictible, even on the ledges.
so the real question is: how do you return to the stage safely against someone abusing a strong u-air? i actually find egg rolling in the air down to the stage to be a solid option. it's about as unexpected by most people than maining yoshi ; ) .
"there better then you?"
at the very least i succeed in grammar of my native tongue, which i'd rather be better at than smash. wow.