The issue list is only increasing here because I broke down the already approved issue into smaller tasks, which individually can help improve the situation. It would allow for a more limited effort while still adding benefit (i.e. not all those tasks need to be completed in order to deliver improvement).
Having said this, I welcome concrete suggestions on issues that should get higher priority. I intend to do some digging myself and try to come up with some.
And we do have active State Channel users here on the forum. The proposal [withdrawn for other reasons] to create a State Channel Mobile Client was well received, and Hypermine (e.g. @vishwas_hypermine) has actively posted on the forum about their State Channel work, as well as talked about their use of State Channels.
In terms of OTP 22, I have pushed a PR, but this ran into an issue with CircleCI. I am waiting for @dincho.chain to take a look at it.
Regarding OTP 23, I suggest that we wait at least until 23.1 comes out. In the initial tests, the build failed due to a compiler bug. This was quickly fixed by OTP, but this sort of thing is not especially unexpected when trying out an X.0 version of OTP. We are also waiting for updates to erlang-rocksdb that would make it easier to build cleanly on OTP 23.
Even so, our intention is to get CI up and running also using OTP 23. The priority for now should be OTP 22, since it is more mature, and has all the things we currently need.