1/3. I'm pretty sure the Pono can run them well, there are 3-4 or ZMF owners with different models that all are happy with their Pono Players. I have made balanced Pono cables for two people, and both of them are happy with the cables, the only stipulation is that I don't own a pono right now and since their system is proprietary I have no way to test the cables before they go out. SO worst case scenario, I'd have to send you a second cable. They are very simple cables to solder though so I wouldn't for-see an issue. I guess I just need to grab a pono!
2. Yes - In theory and practice I believe this to be true, again, I haven't tested though, just based on feedback from owners.
3. See above.
4. Everyone I have spoken with says the new driver membrane is exactly the same with minor changes. We have a good amount of t50rp mk II stock, but plan on tuning to the same FR master curve for the MK III. I will be using the same cups/baffles etc etc for the MK III when they arrive as all we use in the Omni enclosure is the driver. There will be no issue if a replacement is needed. My warranty is one year, and after that I just charge cost of parts to the original owner as long as they hold onto the headphone.
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On a side note. I brought one of each set with the *NEW* and finalized Omni tuning to the Chicago Head-fi meet this last weekend, and the feedback was overwhelmingly positive, so I am ready to declare the Omni good to go and will be proceeding with production. This means the tour sets will go out later this week, and the first production units for the pre-order will ship next week. Here's a pic of the finishing area in it's current state. I'm gonna attack those cups with finish!
On that note, I decided to go with a hand rubbed Varnish for the Cherry and Walnut sets (it doesn't look as good on the Blackwood), which does mean a little more drying time. But the look is worth it IMHO. I'll post a few pics later of the first production sets with the hand applied varnish. Think "sexy violin."