Posy is right about black spot weakening the rose. I've tried ignoring it and had entire roses defoliated and as a result have lost them. It's also important to remember that the ground they have grown in will be infected so it isn't wise to plant new roses in it.
Queen Elizabeth rose is virtually indestructible... a bit of black spot won't kill it or weaken it, and at this time of year it's perfectly normal... it just depends how much one can tolerate in roses... ...if it bothered me that much I wouldn't grow roses..
Posts
https://forum.gardenersworld.com/discussion/1030843/fungicide-worries/p1
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
...if it bothered me that much I wouldn't grow roses..