A) There is no organ for document submittal or review from the limited options here B) You assume that this will supplant printing costs. At $700/per (assuming iPad and case) + $30/month for cellular data, you're looking at ~$1,100/year/iPad. They're fragile and small compared to printoffs. Construction sites are rough places. Dust, dirt, sand, rain, idiots, you are dealing with everything here. If an iPad lasts 6 months on a construction site, you're doing it wrong. C) Printing costs of $3500/$1munit means that to break even, you need only 3 iPads per $1million job. That's 3 sets of plans, aka 3 supervisors. Highly improbable.
Again, as a field construction engineer, I'd love to have a rugged tablet that would be useful, but in terms of idiot-proofness and reliability, nothing's going to supplant a full size plot or clutch of 11x17s anytime soon.
The big construction companies are the same ones that require 4 signatures to activate a corporate cell phone. Please consider the path before sinking too much more time and effort.
You're in the SF Bay, so get Granite or Teichert on board, and see if you can move from there. A pilot case study showing how often they're broken, etc would be a good plan.
I'd personally pivot into rentals. Rent the iPad + plangrid package at a rate of $100(?)/month/iPad. Construction companies are much more open to rentals even if they don't save money than capital expenditures.
If you'd like more background or insight into a field engineer trying to bring his small corner of the industry into modern times, feel free to shoot me an email: tommytgt <at> gmail.com