Job Launchpad may need a protection against LFN sandbox

We had a case where

1. A user used the DIRAC JobLaunchpad WebApp specifying a LFN
2. The "LFN" specified was not a file, but a directory
3. The job started downloading files under the directory, filling up the WN disk
4. The site found the problem and closed the WN, then contacted us

JobLaunchpadHandler simply adds the specified LFNs to JDL
https://github.com/DIRACGrid/WebAppDIRAC/blob/9948d0ef327368ed1e502f41e029f91de3af121d/src/WebAppDIRAC/WebApp/handler/JobLaunchpadHandler.py#L201

JobWrapper simply passes the sandbox files with "LFN:" to DMS getFile
https://github.com/DIRACGrid/DIRAC/blob/fdfd3a4802a5543369d307cbbb3c0781f2f14219/src/DIRAC/WorkloadManagementSystem/JobWrapper/JobWrapper.py#L1127

Can there be some kind of protection to avoid this?
Preferably in JobLaunchpad, with the number of files, or with the total volume?
If that is difficult in the WebApp, then in JobWrapper where it can tell the disk space and the volume of the sandbox?