Please be aware I plan to shortly land a CL to enable throttling network requests in installing service workers as described in crbug.com/1035448
. This works very similarly to how the network is throttled in background tabs. This will affect M84+.
I don't expect there to be any observable API change or breakage to sites. Trials showed that while installs take slightly longer, timeouts do not appreciably increase. The timeout rate for service worker installation remains ~0.1%.
This is intended as an anti-footgun mechanism as we had one partner negatively impacted by network contention from activity in an updating service worker.
Please let me know if there are any questions or concerns.