The BlockingCollection in BinLogReader suffers from severe lock contention:

I added some debug code, and the initial results were:

Read 24924 records in 00:00:06.8023352 = 6802.3352 ms

raising the bounded capacity from 5000 to 50000, I get:

Read 24924 records in 00:00:00.3312354 = 331.2354 ms

which means that >95% of the time spent loading the binlog is spent waiting for a lock.

This is on macOS with the Avalonia version, but I'm guessing something similar would happen elsewhere as well.