This is awesome! Seems a little useless/gimmicky at first glance, but the more I think about it the more it makes sense for home automation. It certainly beats buying (or building) tons of specialized devices for individual tasks, and would enable you to solve nearly any task imaginable with relatively little effort.
The limited space for blocks seems like a potential drawback though. Is there a hard limit on the number of modules that you can fit on a single PI? I can't imagine you could just slap on 5 HDMI output blocks on a single board.
As u/moistbar also pointed out, the number of pins of the Broadcom CPU, and of the STM32 microcontroller, would provide a constraint. If more positions was important, I could easily have put a bunch of IO-expanders or multiplexers.
However, the board was designed with compactness as a priority -- "pocket"-sized and all that -- so as to be portable and flexibly deployable.
The solution for "space" is quite fun: You can chain multiple Pockit boards side by side, through the same style of Bridge-connector that allows expansion to the Display Block in the linked video here.
With this, a huge (but not unlimited) workspace is possible. Frankly, aside from the most spatially demanding application I've tested (a synth/looper setup), I've never needed more than 3 chained together.
> 5 HDMI output blocks
I didn't see the need for something like this. There are obviously compromises in every design, and I suppose this is one of them, if you think it's actually valuable. Though an HDMI splitter block would technically solve this issue too.
The limited space for blocks seems like a potential drawback though. Is there a hard limit on the number of modules that you can fit on a single PI? I can't imagine you could just slap on 5 HDMI output blocks on a single board.