The latest addition on SourceForge download site for my router actually is 380.70.0 and the file with most recent modification date is on top which made me pick the top listed.
Just make sure you don't (re-)post old FW I'd say. Needless to say neither version should cripple the router and if it...
I had been running 380.70.0 on both my RT-AC3200 and RT-AC68U for some days and all of a sudden I get notification today that there is an update. Installed the update from Merlin's downloadsite, weird that it's the same version but hey... and then it said to manually reboot my RT-AC3200. Big...