LGSM isn't in according to POSIX ACL standard

https://github.com/GameServerManagers/LinuxGSM/blob/d86a7095e517f35e7a199169c960166ea45f9c69/lgsm/functions/check_permissions.sh#L11-L26

Hello, I use my rust servers with full acl and these rules aren't in according to POSIX ACL standard.

As example, in a Apache server, the right way to manage FTP (according to POSIX ACL standard) is to create one user per real person and give setgid bit to shared folder. Then users can upload in this directory with shared group ownership but user ownership is set as uploader. So you can give access to Linux users to upload and www-data keep the rights to read/write by group access. https://www.gnu.org/software/coreutils/manual/html_node/Directory-Setuid-and-Setgid.html

But these rules are blocking the server because my users are legitimatly uploading in lgsm server directory. Nothing about any root issue that is explained in FAQ.