Hostname is assigned to an IP, not linked by MAC address?
And how does one access the etc/hosts file? I assume not through either the Almond interface or OpenWRT.
OK, so there are two answers here; the official - it's not supported and the unofficial - this is how you get it done if you really want it
Hostname is not assigned by MAC address, often device type and mac address are used as part of a hostname for users but a hostname can actually be any name. (within reason, special character issues and all of that)
Hostnames are tied to IP addresses. IP addresses, in the case of DHCP are handed out and organized by MAC address and a hostname is automatically assigned, often incorporating a portion of the MAC address and sometimes a little info about the device type.
Stepping outside of the DHCP world and into UNIX in general, hostnames are assigned in the /etc/hosts file and are tied to an IP address.
In order to make changes to an /etc/hosts file, or to even know what an /etc/hosts file is, requires some basic understanding of UNIX, in this case a flavor of LINUX that is used as the O/S for the Almond devices.
You can access the LINUX based OS of the Almond device using SSH. (Secure SHell access) Once in, you can edit files. Again, don't go changing files if you don't know what you are doing and have no understanding of UNIX or say VI.
As it happens, with the A+, yes you can use OpenWRT to access the Network/Hostnames page and make entries for hostnames/IP's.
So, statically assign the IP, DNS and routing info to the client and then use OpenWRT to assign the hostnames to the IP's.
Let us know how it works for you. Haven't bothered to do it myself yet, no real need...yet.