hi dannL

you might call rockland colloid and ask them.
they might have data on that subject .. but from what i remember ...
they stopped making that recommendation because it degraded the emulsion ( afterwards ) ...
one way i have increased the speed of my emulsion is by letting it age a little bit.
i have noticed it gets a bit more contrasty and speedy if it is older ...
are you using it in the darkroom or as a negative-material ?
depending on the outside light the speed changes .. more blue light the faster the emulsion is ...
i did my best to try to figure out what time of year the most blue light is .. ( new england )
and mid day ( 11-1pm ) without a cloud in the sky ... usually in the summertime
BUT ...
and you are making photographs in the snow/winter, you get reflected blue light as well as atmospheric ..

hopefully i haven't disinformed you too much !

good luck !
john