The things I have found about silicone bakeware is:
(1) They need a metal support frame or cookie sheet when full of batter. Careful not to let it fall out as the flexibility doesn't support heavy batter well (though it's great when getting cooked items out)
(2) Browning is minimal.
I don't know that you could get the bakeware hot enough for what a Yorkshire pudding recipe calls for. It's supposed to be poured into a smokin' hot pan. But, mine (Futura) has heat resistence is 230 degrees C and 446 degrees Farenheit. Maybe you still have your paperwork with stats?
But, I don't see why the part rising above the pan wouldn't brown for a yorkshire pudding. But, don't most recipes call for a 450 degree oven? Close, huh?
You see I haven't yet made Yorkshire pudding in my silicone pan, so - gee, care to report back?
(3) If it's a detailed fancy mold, the design appearance is not crisp edged and pronounced, again, because of the weight of the batter.