According to logic, the weight to be carried by an entry should have a demonstrative effect upon the outcome of a race. In fact, the old Jockey Club method of weights and scales, is still used by racetrack handicappers pretty much everywhere, to assign varied weights to the entries in a race, in order to equalize chances of winning and thus level the field of competition.
The racetrack handicapper has done the work
That said, in practical handicapping terms regarding impost, since the racetrack handicapper has already done the work.
Other than in two specific cases, it will be for the most part inconsequential.
However, handicappers should raise an eye brow any time a horse receives an allowance of 7 to 10 lbs, as usually associated with an apprentice rider.
As well, whenever european horses racing in their first American race are getting in light at 126.