Great news, I love the idea of a double-charger, while the shutter release cable is of no interest whatsoever for me. I use an L-Bracket on both my X1D bodies (I do landscape only) and:
1. The design of the little door means that you need to change the setting of the vertical part of the bracket through an Allen key when you want to use the cable release, which when in the field I find even less convenient than having to pair a phone, especially under adverse weather conditions;
2. Using the cord under rainy weather is a no-go (the little door has to stay open = no weather sealing), while the app or delayed release both work just fine in any weather;
3. Even when I can't use the delayed release (i.e., catching waves at the exact time), the lack of vibration of the X1D's leaf shutter + a sturdy tripod / head combination (RRS TVC 33 + Arca-Swiss P0) resulted in zero frames lost to vibration in 6 months of intense use.
Just my .02 of course
Best regards,
Vieri