@Bill_Kuhns1: Insync uses the umask, user id, and group id of the account running it when creating files. The user id and group id cannot be changed, but the umask can be set before running Insync so that created files will have the specified umask. It can’t be set per account though, because the umask, user id, and group id values are set for the whole program.
I don’t see an issue with changing the owner and permission values for the files in the Insync folder since you’re running Insync as root, so it can access them regardless. However if they are updated by Insync the owner and permission values will probably be overwritten, which could make them inaccessible to the other users in your system.