Considering what you must have paid for some of the best brass on the marked, I wouldn't make any changes in the flash hole size. If a larger hole performed better Lapua would have punched a bigger hole. I'm one who subscribes to the "smaller hole = longer flame" theory which (IMO) translates to more even ignition.
As long as you don't have a problem with your decapping pin getting stuck in the flash hole, I would leave them alone. Lapua is some of the best made brass out there and the holes should be very consistent. More people seem to have better luck with any of the small flash hole brass by just leaving the flash hole alone.
Just to add to Corey's post. IF your decapping pin is getting stuck on the flash holes like he mentioned . The ONLY tool to use to ream out the flash hole is the Sinclair Part number 749-005-418 SV. This is the tool recommended and used by benchrest shooters if they have the sticking decap-pin issue.