The problem with a queue on SQLite is that every successful read implies a write. SQLite is fast enough that it may not matter, though.
SQLite also supports in-memory databases with shared cache.
https://www.sqlite.org/inmemorydb.html
If a message queue does not require any form of persistence, writes don't sound like an issue.
Sometimes this is fine.
But that was ... gremlins. More than one person tried to figure out wtf was going one and eventually it was better business wise to declare 'gremlins' and everybody involved in the incident has been annoyed about not figuring it out since.