Unexpected full scans when synchronizing

1. install Nuxeo 7.10
2. install Drive 2.5.4
3. create 2000 folders and more than 20000 files (use scripts attached if necessary)
4. in the logs, one can see there are several full scans. In the 2.4.8 a customer reported many scans. In the attached logs, one can see 3 full scans after the synchronization begins (uploading the files to the server):

   2017-09-20 11:51:29 25328 123145320988672 DEBUG    nxdrive.engine.watcher.local_watcher Full scan started
   2017-09-20 11:51:30 25328 123145320988672 DEBUG    nxdrive.engine.watcher.local_watcher Full scan finished in 847ms
   2017-09-20 11:51:30 25328 123145320988672 DEBUG    nxdrive.engine.watcher.local_watcher Full scan started
   2017-09-20 11:51:42 25328 123145320988672 DEBUG    nxdrive.engine.watcher.local_watcher Full scan finished in 11363ms
   2017-09-20 11:51:42 25328 123145320988672 DEBUG    nxdrive.engine.watcher.local_watcher Full scan started
   2017-09-20 11:52:56 25328 123145320988672 DEBUG    nxdrive.engine.watcher.local_watcher Full scan finished in 73978ms
   

Depending on the server load and the different operations made, the full scans can be very costly.