Make Snowflake recognize FascistFirewall
Snowflake takes a long time to start a connection when a firewall is blocking outgoing ports. If the tor daemon or Tor Browser is configured to connect only to certain ports, then Snowflake could recognize that setting and not take so long to start a connection. Right now, Snowflake stalls when that setting is enabled, regardless of a firewall.
In the tor daemon, the settings are
ReachableAddresses. In Tor Browser, the setting is located at
Settings --> Connection --> Advanced --> "Configure how Tor Browser connects to the internet" (Settings... button) --> "This computer goes through a firewall that only allows connections to certain ports" (80,443).
Going further, Snowflake could assume after certain conditions also that Tor Project's ReducedExitPolicy is enabled in the firewall.