Recommended Dropbox (Formally Google Drive) and Plex Mount Settings

My backup rclone copy command needs to check 1.5 Million files each day, and for about 2 hours it seems to be to check if there are new files. Only after 2 hours it starts transfering new stuff.

Is there a way to speed up the process of it?

e.g:

2018/11/30 16:03:57 INFO  : 
Transferred:   	         0 / 0 Bytes, -, 0 Bytes/s, ETA -
Errors:                 0
Checks:                 0 / 0, -
Transferred:            0 / 0, -
Elapsed time:   2h15m2.2s