When to use unattend.xml in task sequence - best practice?

Question

Hi, I've tried researching this but not found an answer to my specific query.
We have ConfigMgr 2012 R2 with MDT 2013 although I don't think this is an MDT specific question.
I'm trying to create a Build and Capture task sequence for our Windows Server 2008 R2 and Server 2012 /2012R2 server builds utilising an UNATTEND.XML file to make some customisations that can be deployed for every build afterwards in a Deployment Task Sequence.
Specifically the addition of some Windows Features like SNMP and it's configuration and the addition of the Telnet Client. There are other bits like language settings and configuration items but I'm specifically interested in the Features part for my question.
In CM 2012R2 you now have the option under the "Apply Operating System" to use a captured image or an original installation source. However they work differently if you specify the use of the same unattended answer file.
The "image" deployment ignores all of the "add features" sections of the XML file and the "installation source" loses the  configuration options from SNMP from the XML file. When you then deploy the captured image using
the same unattend.xml again the one from the "installer" now has all the SNMP features required and the one from the "image" is still missing everything.
So my question is as follows.
What is best practice for specifying an unattend.xml file in a task sequence. Is it in the build and capture TS or in the Deployment TS ?
or
Do I need multiple XML files, one for build and capture with some bits in and another for deployment with the rest in?
or
Should I be doing something else?
Although this is specifically asking about Server O/S we will be using the same methodology for Windows 7 deployment.

Answer 1

In this case DISM is only used to add the actual features... for configuration you could use a simple script that runs afterwards. Sample registry file:
SAMPLE REG FILE - HKLM-SNMP.reg
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SNMP\Parameters]
"NameResolutionRetries"=dword:00000010
"EnableAuthenticationTraps"=dword:00000001
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SNMP\Parameters\PermittedManagers]
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SNMP\Parameters\RFC1156Agent]
"sysServices"=dword:0000004f
"sysLocation"=""
"sysContact"=""
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SNMP\Parameters\TrapConfiguration]
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SNMP\Parameters\TrapConfiguration\public]
"1"="127.0.0.1"
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\SNMP\Parameters\ValidCommunities]
"public"=dword:00000004
Sample batch file:
SAMPLE SCRIPT FILE - ConfigureSNMPService.bat
@ECHO OFF
net stop "SNMP Service"
regedit /s HKLM-SNMP.reg
net start "SNMP Service"
Also some settings for SNMP can be controlled through group policy:
http://serverfault.com/questions/285762/group-policy-for-multiple-snmp-permitted-managers