Yeah, if you were thinking something more along the lines of a Victorinox folding metal package I would increase the cost, eliminate the manual option, and reduce the concealability even further.
Honestly, though, a simple hinged design that makes the shield take up 50% less space would allow you to carry it slung or on your back with minimal issue. In this configuration I'd require a Ready (Item) simple action and a simple action to unfurl it, which could be reduced to a free action with wireless. That way you could ready it and unfurl it with a free + simple and quickdraw a holstered or slung weapon and fire, all in 3 seconds. Sounds about right to me, though a Victorinox Shield Bracer that is worn like a bracer of old and transforms into a fully formed shield with a wireless command sounds pretty bad ass too.
ETA:
It's worth noting that some of the Baker Ballistics shields are actually worn strapped to the forearm, and allow operators to normally wield a foregrip. As such, you wouldn't even need to fire a weapon one-handed, and could use it mostly normally. I'd probably still apply the general -1 Physical limit modifier for having an unwieldy piece of metal strapped to your forearm, as per page 438 of SR5.
