Server crashes on login due to server tick taking 60 seconds

I was out and about making a map when the server crashed. I restart the server, but every time I log in, the server crashes again. According to the server log, this is the reason for the crash.

[06:45:04] [Server Watchdog/FATAL]: A single server tick took 60.00 seconds (should be max 0.05)
[06:45:04] [Server Watchdog/FATAL]: Considering it to be crashed, server will forcibly shutdown.

My hunch is that I'm surrounded by a lot of ungenerated chunks, and chunk generation is causing the server to hang. I believe this is also being exacerbated by MC-149018.

I've attached three crash reports. The world seed is 6639103587653769273.