We've published the slides from the Open Simulator Community Conference in 2019 as requested. You can find these linked at:

SceneGate for OpenSimulator

https://www.slideshare.net/LisaLaxton/oscc19-sg-01

EchoVoice for OpenSimulator

https://www.slideshare.net/LisaLaxton/oscc19-vo-ip05

Please contact if you have any questions!