TT is awesome and it’s free, but it’s got about the lowest resolution and least sophisticated snowfall algorithms of every outlet, except maybe those 1986 Donkey Kong level maps ncep still puts out on their defunct page they still update for some reason.
And even if the TT maps were the most accurate using one that round to the nearest whole number in a C-2” event seems like an interesting choice.
Again, just look at the raw QPF, apply what you think the ratio should be, and be done with it.