Seems reasonable that a calf that weighs more at birth would have a head start on weaning weight over a much smaller bw calf. But we know that the continental breeds came to the US with very high and very undesirable birth weights. Through selection, those birth weights have been decreased significantly while maintaining growth.
There is a simmental/simangus operation in Alabama that runs about 800 cows and sold 180 bulls last year. Seems like most of the bulls they use tend toward calving ease and low bw. For their annual production sale, they publish bw and ratios, weaning weight and ratios, yearling weight and ratios and frame score. From the data published, I can't see that they are suffering on growth. Of course, they are selling the better bulls with the rest going to the feedlot and we don't see the data on those.
Looking at one sire group (calves sired by the same sire), these are the birth weights and weaning weights on the 7 calves sold in that group: 59# and 781#, 61 and 799, 77 and 779, 75 and 825, 64 and 731, 61 and 705, 74 and 797. All weights adjusted for age of dam and for 205 days. The sire is top 10% for CE in the simmental database, top 25% for BW, top 25% for ww, and top 15% for yw. Frame score on this group was from 5.2 to 5.9. Full disclosure - the sire group I picked from the sale catalog appears to have the biggest spread of bw to ww. So this group does not reflect the average. But on the average, they seem to be doing well on growth with their CE bulls.
Also, I think that optimum birth weight varies by area. Those continentals from the late 60's must have fit the needs in Europe, but not here in the US as far as CE and BW. Final and maybe most important point - seems that selection for most traits needs to not be for extremes either way. Long term, selection for extremes will result in extreme cattle if replacements come from the herd. Chasing maximum growth (or milk or CE or BW or marbling, etc) might lead to an undesirable destination. Less concern if all calves go to market, but be aware of interactions of one trait on another.