My testing of light modifiers before jumping at the 165cm umbrella has highlighted a few things.
All mods are good at something and any can be good at what you need with a little grey matter applied.
Some of the cheaper mods are by far and away better value that the dearer ones and usage trumps purchased expectation, which is to say, there was more variation just in stem length used with my brollies, than between some very different mods.
A 165cm white reflective brolly would not add much to my setup. My 7’ white or silver are softer and wider covering, my 42” white brollies are versatile and nice, my 4’ Octa soft boxes are under-used, being user friendly and versatile.
Reflected is preferred over shoot through for me.
Control is a more important addition to my setup, something the black backed brolly would add, but egg crate grids would do even better.
All mods should be bought with grids if available.
Instead of a big white brolly, I went a second set of 2x 4’ Godox octagon silver/diffused brolly soft boxes, but with grids, for the same price as the single brolly.
A good base and consistent. Not the best light I can do, but versatile and always useable.
This will add the following;
2x more (4 total) 4’ deep silver or diffused white mods, which could make a massive 8x8’ wall of light with decent throw and enveloping coverage. I have enough 3m+ stands and flash units for these (with 1 of each to spare),
2x egg crate grids for any two of these which I feel are the best investment,
2x spare diffusers for two of them go double soft (which does make a slight difference),
2x spares for longer term durability, guaranteeing 2 at any time.