Someone's surely going to call their support line and give that a try.
You could be that Someone
On a semi-related note, I received a full complement of O-rings intended for long-term maintenance of my half dozen 525SS faucets, and as a result I've come to realize the 525SS went through some evolutionary changes over its lifetime.
For example, the original large O-ring used to seal the spout on my Perls is larger in all dimensions than the O-rings I just received from Perlick.
As well, the faucet lever on my set has a round section in the shank where the new levers have a square profile - the former allowing the whole lever to rotate without restriction (save for the resistance provided by the faucet lever pivot ball O-rings), the latter preventing much if any rotation relative to the bearing cup (which has a rectangular opening for the lever).
And speaking of the bearing cup, mine are nylon, but what Perlick sells today are stainless steel.
A couple of summers ago there was a sudden rash of folks complaining about leaky Perls, while longer-term owners were feeling pretty darned good about their faucets (myself included in the latter group). I'm wondering if the O-ring change and/or the bearing cup change could have been related (the lever change seems unlikely to be contributory).
I'm a bit apprehensive about the O-ring change (I mean, there has to be an answer to why the Perls apparently got so cranky) so I'm conducting an experiment on one of my faucets to see if there's going to be a closure issue with the new O-rings. I stuck a seventh keg in my keezer with a gallon of water, swapped the lines from one of the beer kegs over, then pulled the corresponding faucet and swapped out the #3 O-ring. Initial results seem solid but I'm going to mess around with this over the next couple of days to see if it's touchy or reliable.
fwiw, I spent quite some time looking for dimensionally equivalent replacements for either the old or new "#3" O-ring and came up dry. There's a chance that both versions were custom made for Perlick...
Old Style #3: .67" OD, .40" ID, .140" thick
New Style #3: .635" OD, .375" ID, .135" thick
Cheers!
[edit] Just to be clear, I've been running these faucets for a few years now and they've been rock solid, never leak, always connected at 12psi...