Most useful modifier for those using off camera flash?

I'm curious as to what you guys/gals are mostly using for modifiers on wedding gigs. I'm looking at picking up a Godox/Flashpoint 600 monolights and wasn't really sure which modifier(s) are 1) effective and 2) practical for weddings. It'd also be helpful to know whether you use assistants or you fly solo.

1. A wall.
2. A ceiling
3. An off camera light in an 18" soft box, carried by my assistant
4. A shoot through umbrella, for first dance only, and only sometimes.
5. A black foamy thing.

That's all I use. I use direct flash outdoors, diffusers for on camera flash make no difference. I don't use diffusers for group photos beacuse unless you have a 1m / 3 ft diffuser really close they make no difference.

I have had all kinds of diffusers - Fong Dong, on camera soft box, a little plastic thing that clips on to "diffuse light", etc. They're all marketing gimmicks. Understand light and you won't need much.

I use many. Typically scout locations first and determine what Im going to bring.

Outside im using the Ricebowl and a 33" foldable BD from cheetahstand

Outside super bright light and im using the 45 longthrows from cheetah stand- these are amazing mods

Walls & ceilings inside are first choice with demb flips and i make my own black foamy thing, stofans come in handy at times as do video lights. Too many options to consider for inside use