First post, but I thought I would chime in regarding the comfort of the DCA E3 headphones. When I first unboxed and started to use the headphones I initially experienced a pressure point at the very top of my head, in the center of the headband.
I tried removing the headband and breaking it in with my hands, but the E3's automatic size-adjusting elastic band is housed within the outer portion of the headband and these regions can only be broken in so much (I was hesitant about bending or placing pressure on these attachment points). As a result, breaking in the headband eliminated the pressure point at the top but introduced two pressure points closer to the side.
I also own the DCA AEON 2 Noire headphones, so I then experimented with using the DCA AEON 2 Noire headband with the DCA E3. I experienced the following issues:
1) The wire frame chassis of the DCA AEON 2 Noire is separated by a consistent gap (like train tracks), but the gap between the wires on the E3 becomes wider as you move away from their attachment point. This means that moving the headband from the DCA AEON 2 Noire over to the E3 requires clamping down on the wire chassis, bending them, and making the chassis-headband attachment points (black plastic pieces) less mobile. If you have a small head, I do not think it would be feasible to clamp down on the wire chassis to degree required to attached the headband close to the origin point of each wire.
2) You cannot transplant the arms (and wire chassis) from the AEON 2 Noire to the E3 because the ear cups have different dimensions and, as a result, so do the arms and yokes.
3) The DCA AEON 2 Noire has two attachment points (black plastic pieces) for the headband that can move freely to adjust the fit of the headphones. If you remove the two black plastic pieces by unscrewing the screw used to attach them to each other, you will find a smooth plastic washers on each wire that is used to help the attachment points move along the wire chassis. This is attached to the wire chassis and cannot be migrated, introducing friction and making the AEON 2 Noire headband less mobile if migrated over to the E3 wires.
4) The E3 ear cups are relatively heavy and this additional weight is supported by the upward force provided by the elastic material used to attach the headband to the chassis. As the AEON 2 Noire headband is just a static piece of leather, using the AEON 2 Noire headband resulted in the heavier ear cups drooping lower without the necessary upward support, reducing comfort somewhat.
In light of these issues, I reached out to ZMF and asked them if they had an recommendations for an aftermarket pad to go with the latest DCA headphones (including the E3). The ZMF employee that responded to me mentioned that the Co-Pilot and Crescent Snap headband would probably work well, but I was not able to purchase the Crescent strap in my region and decided on the Co-Pilot pad for the time being.
I can say that the ZMF Co-Pilot pad works very well with the DCA E3! The added thickness of the pad does increase the tension in the E3's elastic bands somewhat, which does make the ear cups ride a little higher and might not be great for the longevity of the elastic band itself (though this probably is not a big deal unless your head is very, very large to begin with).
Ultimately, I was feeling pressure points after one hour and now I can wear the E3 headphones all day without issue.
Here's a link to the products I mentioned:
1) ZMF Crescent Snap -
https://shop.zmfheadphones.com/collections/pads/products/crescent-snap
2) ZMF Co-Pilot Pad -
https://shop.zmfheadphones.com/collections/pads/products/copilot
I hope this helps somewhat.