I am writing a midi polyfill, to bridge Core Midi with Safari. This, in itself, is not a problem. The problem is that the Web Extension will get suspended the moment it's no longer actively called. This means that no callbacks due to midi changes from core midi can be passed back to the web page.
If I use a setInterval call in background.js, then this keeps the extension alive somewhat, but the setInterval self ping will get aborted eventually, making the Extension suspend itself.
I know of a fairly contrived workaround using the container application over XPC, but I am hoping there is a way to keep the Web Extension alive - or at least keep a thread in the same process as the Web Extension alive. Or any such workaround. Setting background to "persistent": true does not seem to make any difference.