@Stokkes I had quite bad experience with acd_cli once my library got over 25TB.
My setup is 1x server that downloads/uploads new media files and 1x Plex server.
acd_cli is beyond allergic having multiple mountpoints and changing content one one side.
The biggest problem I had was database corruption and inability to preform full sync in one iteration eg if I deleted corrupted sqlite db I needed to run sync at least 3 to 5 times before it was done and for each sync i needed to wait 5 minutes in between. That meant that mount would be disconnected during all that time and that made it completely unusable as it would mean on db corruption i would be without mount in average 15 to 20 minutes.
According to acd_cli docs when any changes happen on acd the remount and sync should be done.
At the end I had like 100 lines bash script that was checking if acd is still connected making a copy of current sqldb if sync error occurred ( and it was happening quite often,especially if I added 100+ files ) so i could restore the previous db etc...
I think the only advantage acd_cli have atm is local cache of file/folder structure ( ncw is already working/planing on it for clone ) and with that you can shave off 3 to 5 seconds that rclone needs.
Keep in mind there is still "missing files" problem with acd_cli where some of the files wont be shown at all ( it should work with previous 31 version )
p.s. Rclone had major issue with seek in crypt mounted files that were fixed so you could test it again with latest version.