There is a guest access security bug on 4.1.8-T5.
I just updated an NV+ to 4.1.8-T5 and all three of my shares with AFP enabled showed guest access as enabled under Shares > Share Listing in Frontview.
Two of my shares which I had set with read/write set as the default access for the share over AFP, the guest user was able to access over AFP.
The share which I had default access set to disabled, but had a write-enabled user for, the guest user was unable to access (well at least it didn't show in the list of AFP shares).
Whilst not as severe as the issue on 4.2.18 for x86 (I think), this is still a security bug.
