wrt the issue of phones going to sleep and disconnecting

so the tech we want to use is called Screen Wake Lock API

however, it looks like it requires https, so it may be awkward to implement for locally served websites, such as is used by the DX∑.

this issue came up a few years ago when using AudioWorklet to do phase modulation based formant synthesis, which also requires a secure connection. although it is possible, the way the web protocols work would require participants to disregard scary warning messages:

scary warning