Most likely when I need new UCA ball-joints, I'll re-use the arms and press in new ball-joints, as I do in my 1960's cars (screw-in in Mopars). The main reason is that I hate to waste good parts, like the UCA aluminum. But other reasons are that it can save cost and, most importantly, I can control the quality. When you buy a new UCA with bushings and ball-joint, you don't know what parts they installed, but Chinese is a good guess. The UCA sees little force since the spindle gives it a long lever arm. All I've had to do on my 1985 300D (now at 380K miles) is replace the rubber bushings on the sway bar connection since they fell apart to cause a rattle. That is fairly easy as no pressing is required (tapered rubber). I recall having to unbolt the UCA pivot to swing it out. I did have to replace the lower ball joints (recall, might have been just my 1984 300D).

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans