Because I use dump for backups, I always create a separate partition for
/home.
If it is part of "/usr" and want to create a backup with dump, you have to backup everything in "/usr". Then the backup includes the "/usr/{bin,sbin,local}" directories which roughly make up 80% of the FreeBSD base install. So by having a separate home, you have to backup less
I don't know the amount of disk space you have reserved for FreeBSD , but I would suggest to increase "/usr" from 5 to 10 GB.
Whatever you choose, most users after finding out how much space they actually need, usually will reinstall FreeBSD after one or two weeks anyway