[pjz]

re: presentation remote controls:

  Look into remote controls for, say, Kodi.  You're sure to find the wiki listing a bunch of ways to control Kodi from your couch, which includes bluetooth remotes of various flavors that should meet your needs.

re: zigbee being underused:

  ...they're expensive.  I don't know if it's licensing or what, but zigbee SoCs are 5-10x the cost of, say, an ESP32 wifi SoC. $10ish each vs $1.25 ea at a quick glance.