How many should i bring for bmt ?
5 or so should be enough. If i didn't remember wrongly, the standard display only allow you to hand 1-2 sets of number 4 and the rest must all be folded neatly anyway so hangers are only used during normal times. Most people can't be bothered to keep refold uniform when going standby so just don't hang.
Now sure whethere any changes in the display format and might depend on how strict your specs are with it cos mine were pretty strict in ensuring we follow every single detail in it.
none
I have 8 in camp.
1 for smart 4 shirt.
1 for smart 4 pants.
1 for admin shirt.
4 for display.
1 someone abandoned, so I use it to hang socks.