I vote "wont fix". Users who need good performance should enable CLI support.

we added the "Cli support of Processes" to the system check so users know whether their piwik setup has CLI support or not.

This isn't for people who don't have support for CliMulti, it's for people who experience bugs w/ it and don't want to wait until we can reproduce it. Falling back on synchronous curl requests for weeks or potentially months seems like terrible UX. And I can't imagine the speed benefits from using processes instead of HTTP requests will be all that great (if even noticeable) for users whose visits number in the millions and billions where the bulk of the archiving process consists of aggregation.

If there is an issue or bug with CliMulti we want to fix it asap. it's not terrible UX to fallback to Curl, it just works (but is slower & with its own problems such as HTTP timeouts etc.). We decided few weeks back to remove support of async curl because code was quite ugly and hard to understand. Also we push for CliMulti going forward and are committed to make it super stable. If users don't want to wait that we reproduce, they should send us SSH/FTP access 👍

I think it's terrible UX to fall back to synchronous curl requests. And it wasn't just the async curl code that was ugly, it was the entire CronArchive class. In fact, I remember that the bulk of the async curl code was in just one method. It would not be difficult to refactor the CliMulti code to allow async curl requests and would create an opportunity make the code clearer (I wouldn't call the current code pretty).

This is the last I'll post on the topic.