what you want to get is some larson soff boxes ... or strips
the old ones sell on eboink from time to time, they are worth their weight in GOLD
larson has sales every week ( get on their email list ) sometimes buy one get the 2nd FREE ..
the thing is any diffusion / modifier eats light, sometimes a stop, sometimes more or less.
umbrellas are OK but depending on what skin is on the umbrella it can be contrasty or not enough
boxes give nice soft faux north light ... and larsons last forever.
i have a few old ( like 30 year old ) larson boxes and a chimera ... the chimera is junk by comparison
if you have hot lights, be careful, a lot of boxes can't take the heat, so you might be stuck with using
umbrellas whether you want to or not ...