Update 2020-03-07
New
Cable Glands
After reading through the Show us your enclosure insides thread, I wanted to keep the build both clean and as water resistant as possible. After some shopping I arrived at a TUPARKA 50 pack of cable glands. Current plan is to run (2) holes in the enclosure, one for each motor, using a PG13.5 gland. Each will house the (3) phase wires and the sensor cables.
BMS
Committed to the Neptune 15 (although it is taking its sweet time arriving from Hong Kong). I’m currently debating adding a fuse the to charging port leads since this BMS already has short circuit protection. I will likely wire this as charge only, but as @Nikos notes there is a 100A discharge mod for this BMS. 
Battery
After gathering the feedback on battery cell selection (thanks!) and doing additional research at the following sources:
- 18650 Battery Cells Thread
- 18650 Insulator Rings - Redundant?
- What’s inside an 18650 cell? And why its important
- e-cigarette forum List of Battery Test
- Mooch’s YouTube channel
I decided on Samsung 30Q cells and will be adding an additional fish paper ring to the top of each cell before loading into my N.E.S.E. enclosures.
Arrived
Maker X GO-FOC SV6
Really impressed on the build quality here.
Since the 12AWG leads come out the side on these, they are a tight fit in the enclosure as I originally planned (see my dimensional drawing from my original post). I’ve decided that putting pressure on these leads will likely lead to a failure over time so I have altered the layout of the VESCs and BMS in the enclosure to address this:
In this configuration, the leads of the “top” VESC will need to do a 180 and run up the inside of the enclosure, reducing the pressure on the leads. This means that the phase wires will all point toward the middle of the enclosure where they will mate with the connectors from the motors before traveling through the cable glands. Hopefully this keeps cable clutter to a minimum.
Antispark
This arrived and looks good. I’ve added XT60 connectors to each end, although I may shorten these leads depending on how bad the cable clutter gets.
Changed
Nothing this time
Completed
Lugs to Main Battery Leads
I crimped and heat shrink covered the lugs to a female XT60 connector to be used as the main battery leads. I think it turned out rather well:
Charger
Pulling in the power supply, a three prong pigtail, and the CNLINKO M16 connector I was able to complete the DC charger for the board:
Additionally, I adjusted the potentiometer and leveled the charging voltage to 49.8v, which should provide a peak P-group charging voltage of 4.15v. Looking at various battery datasheets, it is suggested that 4.15v be used when charging cells which are cold (0degC - 10degC or so) to maximize battery life. Essentially, this voltage (and current) should provide optimal charging characteristics for the cells, even in the least optimal circumstances.
What’s Next
Padding
With most of the internals on-hand, it’s time to consider how to mount these components in the board. There seems to be (2) schools of thought here: mount to the board or mount to the enclosure (if the enclosure is up to it). With the eBoosted enclosure I’m not really worried about structural integrity 
so I’m heavily leaning toward mounting the hardware to the enclosure. After looking through the forum, neoprene foam and industrial Velcro appear to be the materials of choice. I’m thinking of skipping the Velcro entirely and simply using the quantity of foam which will hold everything in place and buffer the internals from vibration and impact from both the deck and enclosure.
Balance Wires
One of the great things about the N.E.S.E. enclosure is the ability to easily replace a bad cell in a P-group. Keeping the lids the N.E.S.E. modules accessible is therefore an important consideration when building the battery pack. Using the padding noted above as a launching point, I have decided to run the balancing leads behind the pack in channels made by tiling the foam. Additionally, I’m planning on using wire guides made from 100mil blank headers (drilled out) to ensure a clean wiring harness (of sorts) for the balancing leads. Leads will terminate at ring terminals connecting to the positive terminal of each P-group.
Custom XT60 Splitter
With the new component layout, the way the antispark connects with the VESCs has changed. Essentially, each VESC’s XT60 will come from opposite sides of the enclosure and the antispark will be aligned with one of those XT60 connectors. This means that I will need to run an XT60 splitter with both male (connection to antispark) and female (connection to one VESC) connectors on one end and a single female connector (connection to second VESC) on the other. I could use a standard splitter and just double back one end, but a custom splitter will reduce cable clutter and be more robust. See my updated wiring diagram above for an illustration.
Research
Wheels and Tires
The jury is still out on wheels and tires.
First, it appears that the most recent iteration of the eLofty drives ships with a Kegel adapter with fewer pins and compatibility with the TorqueBoards DD adapter dimensions on Janux hubs see here. (Thanks @visnu777) This means that there is no need to buy the special eLofy Janux hubs, and I can instead purchase the TB DD hubs (which gives me more flexibility in the future).
Second, it appears that @Arzamenable has mounted Evolve tires to the larger Janux hubs see here but I’m still waiting for final confirmation of this. If so, this would make for a really flexible hub which could use the following wheel options:
I’m hopeful this is the case. Since we are still in somewhat early days for DD + Pneumatics, having the flexibility to alter the external diameter of the wheel by this amount (without changing hubs) could be quite helpful when dialing in ride quality / torque / etc.