I just got my ZNA back from the shop. I had a serial 611, so the redesign (not being aware beforehand) was enough for me to call Zen. He was extremely helpful and explained why he introduced the new design to prohibit flattop
batteries. He was getting a lot of units back from people that had inserted
batteries the wrong direction. Plus he went in depth on his preference for using AW IMR
batteries in the ZNA. I won't try to recite it, but one thing I took away is that he said I should get a more true battery reading with AW IMR batteries.
The top cap redesign took a lot of finagling to get my Russian to sit flush. I had no problems adjusting the old top cap, but this one took a lot of work. In the end, I had to file down the bottom side of the copper so I can screw the top cap all the way down. We're talking less than a millimeter and it wasn't a big deal because copper is so soft. Not a huge fan and I know he had good intentions, but the copper is really easy to gnarl up when back the pin in and out.
Anyways. I'm all adjusted and 100% back in business now. Extremely happy with HoH support and the ZNA in general.