Hi leafo, thanks for all the hard work! I found out that SharedArrayBuffer is not enabled on Safari when accessing game pages (EG: https://davcri.itch.io/test-godot4 where I enabled experimental support from the dashboard). This may be due to Safari requiring “require-corp” instead of “credentialless” (https://webkit.org/blog/12140/new-webkit-features-in-safari-15-2/).
I guess right now it’s difficult to find a configuration that works for every platform.