How fast you stocked your display tank has to do with why your fish have ICH IMO
No one is dodging the question, the tank is not cycled and will not be any time soon, so if you plan on putting those fish in there now you will have to do many water changes to keep things in check. Not sure what answer your looking for.
And adding that many fish to a 40 and housing them for 30++ days will be tricky to keep them all alive and healthy.
Seeing you have that attitude, tells me you know you rushed things...
All were trying to do is help and point out what might have went wrong so you and others don't repeat it.
So in case you missed it... The 40 is not cycled, there is no quick way to fix the problem because every cycle is different. So if your looking to get the fish out of the 150 fast your going to have to do many water changes.. Unless you wnat to buy some cured LR
that may help speed things up.. But the LR
will not be any good after if you use copper to treat the sick fish.