For my bromine box I use the recepy of Mike Robinson ( bromine mixed with cristals).
For your bromine – fuming- time … the color in the Bromine-fuming box … is it yellow or lighly orange ?
I mix liquid Bromine with silica gel. I try to get it bright yellow (“post-it” note yellow, if you have that product in your country). I’ve found that as the Bromine color heads into orange, it is too powerful.
I also heat my plates with a blow dryer before fuming to accelerate the chemical reactions.