Yes, we'd also prefer more recent technologies, but these are usually not trivial to find with open-source in mind. The usage time is up to 8h, realistic heavy use scenarios will have ~5-6h. The amount of users is for sure limited, we haven't verified upper limits, but this is clear a "personal" device not aimed for rooms of people. Although this mainly depends on usage intensity - but a handful of users should be no problem - performance will for sure degrade above this.