If the Apeks warranty is voided by using non-Apeks-branded hoses...then I'll sell my Apeks reg ASAP. That would be a ridiculous policy. I could never see a manufacturer placing such restrictions on their warranty. I really like my Apeks regs, and I'd hate to give them up.
I recently replaced my original Apeks hose on my ATX100 with a Miflex hose. I did have to use a thin open-ended wrench in order to tighten the LP hose-second stage junction. After reading the above link, I find it somewhat amusing that the statement blames the Miflex hose for the design issues...when, in reality, the design of the Miflex "swivel" is the same as any other non-Apeks-branded hose.The issue lies with the design of the Apeks Heat Exchanger (part# AP5013) that locks the valve spindle in place on the second stage. The six-sided nut area is thin...for no good reason really. Mating it with a Miflex hose demands use of a thinner-than-usual wrench. Torque for this junction should be 5 N-m or about 40 in-lbs. Most people I know do not use a torque wrench on this junction and usually just snug it up a little beyond finger-tight. If this is how you are doing it, you should always use two wrenches to tighten the LP hose-second stage union since using only one may over-tighten the Heat Exchanger nut into the second stage, causing the plastic housing to crack. More specifically, you would use a regular thickness wrench on the Miflex hose side and the thin wrench to hold the Heat Exchanger/Lock nut in place. FYI, the torque spec for the Heat Exchanger into the second stage is 45 in-lbs.