I don't have what I think of as silver partridge.
Guessing you're talking about what I see as silver duckwing?
I made those myself by crossing cuckoo with brown leghorns.
I do focus on egg laying but color/patterns is what I enjoy.
In the end though I believe color doesn't really matter if it doesn't look leghorn or lay like a leghorn.
I can't compete with a production white but they do alright. You'll find most less available colors lay very poorly. Some of the unusual ones like mille fleur even lay tinted eggs instead of white.
I work to improve production, size and shade if they're off.
I think I have 6 silver duckwing and one blue hens in my breeding pen and get about 5 eggs a day.
Some varieties I get around 50% each day.
I know not the best but I'm working on it.