My mother has a WP DD machine that's at least 25 yrs old. Although it is showing it's age it is still chugging along strong as ever. Once in a while I can tell when the machine isn't neutral draining but otherwise the machine has never been affected.
I attribute this to the age of her machine and considering that it hasn't affected any other operation of the machine it has just been left alone. My mother, I think isn't even aware of the situation but my ears have picked up on it when I happen to be there when the machine is running.
You will lose a little bit of fabric softener when the machine first starts to spin anyway,
but provided you use the correct dosing you won't experience any problem and there will be enough softener dropped into the basket when it stops spinning.