Hey OP (assuming you're the author), you might be interested in this similar experiment I did about four years ago, same dataset, same target, similar goal!
Similar sequence of investigations, but using regular Postgres rather than Timescale. With my setup I got another ~3x speedup over COPY by copying binary data directly (assuming your data is already in memory).
https://rdrn.me/optimising-sql/
Similar sequence of investigations, but using regular Postgres rather than Timescale. With my setup I got another ~3x speedup over COPY by copying binary data directly (assuming your data is already in memory).