you can add the flag --rsyncable when making gzip and zstd archives and they'll rsync way faster and generally less than 1% larger than if you didn't
(it puts little synchronization checkpoints in the file that rsync then doesn't have to calculate on the fly iirc)
e.g. here's some flags i like:
tar -I"zstd -T0 -19 --rsyncable" -cvf stuff.tar.zst file1.txt file2.txt ./directory/to/files/
(note that using --long and --rsyncable at the same time might reduce the benefit to rsync speed since the rolling hash sync points added by zstd are based on the compression window size)
edit: the above example works with gnu tar, but -I means something different with bsd/macos tar. will make another example in a bit
