Did a bit of digging on this beforehand, but didn't come to any concrete answers...
The spring in the socket block of my Master arm broke on the last shoot I was on - didn't even notice it though, only found it when I picked up the arm to suit up and found the socket block flopping around like a dead fish.
The shoot was too chaotic for me to notice a real difference in how it felt, but it got me thinking - do I need that spring, since I'm operating with a Klassen backmounted harness? I saw in an old post that Rob Van Gelder removed his, and said it had no ill effects, but I'm curious if anyone else has been down that road.
It's probably something that I'll replace down the road, just in case I do any work with a front mounted vest again (however doubtful that is, at this point), but it's still worth thinking about!
On a related note, I'm experimenting with removing the stopper from the socket block (the little piece of metal that stops the socket block parallel to the arm, rather than letting the spring whip it all the way around). It seems to be on the wrong side to help me at all when using a backmounted vest, and especially now that there's no spring, I don't need its help to align the socket block into my arm. Has anyone experimented with this in the past, and is it likely that I'll see any detrimental effects from this? I saw Jerry recommending that someone remove this stopper on their Master arm to emulate the kick-back link, so I would think it's fine to do, but I've been surprised before!
Maybe all this socket block playing around will finally convince me to replicate what Larry McConkey built for his arm and remove the rod ends and associated gak from the socket block entirely for backmounted work. One of these days when I've got some time to sit down at AutoCAD and some spare dough to toss at a machinist! That'll be the day!