I will be interested to see if you get samples for testing. From the copper alloy springs I have tried over the years, they tend to be much stiffer than spring steel and they tend to develop a "compressed memory" rather rapidly, but maybe these are made a different way than the ones I have tried out.
If they do get tested first and prove out to be as good as spring steel ones, then I would want to purchase "an amount somewhere under 100pcs, depending on the price", of springs that are in the range of 10mm-12mm bottom diameter, 5mm-7mm top diameter, 10mm-12mm tall and .8mm-.9mm wire thickness.
The manufacturer of BeCu springs claims they can take many more compression cycles than SS or piano wire springs while under current load. The Beryllium alloy is very strong, I saw one that claimed 200,000 psi strength but am not certain the application. At any rate, they highly recommend this allow for springs that do not take a set.
DBCstm has pretty much answered this but BeCu is primarily used in high end musical applications precisely because of it's ability to hold its shape. I really think there is zero worry in regards to 'pancaking'. The silver will prevent tarnishing of the copper if nothing else.
I should point out these springs are proven in the flashlight world. It just seems that no one has posted numbers, but they are regularly used in 6A+ applications.
Obviously I am more keen than most to get my hands on these. Not even trying to hide the fact. I just want good quality, high current springs for drop-ins I make, and my own FET based electronic switch. At the moment the spring I use is the weak point and these springs will basically eliminate that issue (or rather move it elsewhere haha). THe stuff we get from KD, DX, IO etc are sh*t. No two ways about it. The copper braided mod is good, but if your anything like me you will like a bit of style with your substance.
I'm rambling now lol. I'll probably end up ordering a stack of these anyway if this GB goes belly up. Numbers seem good though. Where we at Dale?
You’re currently looking at a box of about 640 springs, more or less.
No answer on my query, I’ll be calling tomorrow. Last night was a horrible night, making today a bugger. Hope to be on the phone with em tomorrow and get some details and possibly some samples on the way so I can shoot em with my macro and make em look Ginormous!
I just realized that Beryllium is a Group 1: Known human carcinogen.
The MSDS sheet says that the beryllium copper alloy is pretty much safe, but please be careful and make sure you’re wearing a mask and goggles when you’re cutting it with a Dremel.
Again! 
