Start forcing to be hero bug?

apparently im trying out to make a hero rapid fire with forcing heroes change.
seems like after looping for a few seconds , it breaks down, in the sense that it slows down the forcing hero part, i no longer swap as quickly as before, a very noticeable delay. appreciate help.

Also, the blue texting showing of hero swap shows as well.

so an example pharah,

rule ongoing -eachplayer
event{
on going each player
all
all
}
condition :
hero of event player == pharah
is button held (primary button) ==true

actions:
set projectile speed 1599
start forcing hero to be pharah
start forcing hero to be ana
start forcing hero to be pharah
set player health max health(event player) - eventplayer.accumulatedeventdmg
wait 0.002
loop if condition is true.

Yes, there is a limit to changing heroes.