Targeting contents using XRANK in SP2013 problem

Lately i had to create a content priority/targeting system in SharePoint 2013, using search capabilities in a public context (so no target audience available).
What you'll find below it's a targeting system based on managed metadata content tagging and dinamically generated queries using XRANK directives.
Let's think about a enterprise model with a hierarchy like this

• Channel 1 (00000000-0000-0000-0000-000000000100)
• Network 1 (00000000-0000-0000-0000-000000000110)
• Agent 1 (00000000-0000-0000-0000-000000000111)
• Agent 2 (00000000-0000-0000-0000-000000000112)
• Network 2 (00000000-0000-0000-0000-000000000120)
...
• Network n (...)
• Channel 2 (00000000-0000-0000-0000-000000000200)
...
• Channel n (...)

This could be represented as a hierarchical term set in Managed Metadata Service Application.
Now, let's assume we have these contents:

• Page A, tagged with "Channel 1"
• Page B, tagged with "Network 1"
• Page C, tagged With "Agent 1"

Following this article http://techmikael.blogspot.it/2014/03/s15e01-kql-basics.html we can target contents using Search.
For example, if i am "Agent 1" and i want to obtain contents in this order

1. Page C
2. Page B
3. Page A

i can use a query like this
(((owstaxIdTargeting:"GP0|#00000000-0000-0000-0000-000000000100" XRANK(cb=1))
owstaxIdTargeting:"GP0|#00000000-0000-0000-0000-000000000110" XRANK(cb=10))
owstaxIdTargeting:"GP0|#00000000-0000-0000-0000-000000000111" XRANK(cb=100))

Basically, i'm boosting contents created for "Agent 1", then contents for "Network 1", then "Channel 1".
Great? No. This method apparently works.
In this query i used XRANK, which boost the rank score... boost means SharePoint assign a score using ranking models you can boost manually using XRANK query directive.
This also means that rank scores could be scrambled by a lot of rank model rules, take a look to this articles:

• Overview of search result ranking in SharePoint Server 2013
• Customizing ranking models to improve relevance in SharePoint 2013

This leads me to think i can create a "Fake ranking model" for those queries, useful only for this content targeting technique.
This model basically assigns a 0 score to all contents and it simply does NOTHING, so only XRANK values will be considered.

?

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<rankingmodel2stage description="A model with does nothing" id="05E6223C-C4C0-4EB7-8E28-8242E48D05A9" name="Fake Rank Model" xmlns="urn:Microsoft.Search.Ranking.Model.2NN">  <rankingmodel2nn id="242B7953-A3EE-499B-B6F5-A473AA33ADFA">   <hiddennodes count="1">    <thresholds>     <threshold>0</threshold>    </thresholds>    <layer2weights>     <weight>0</weight>    </layer2weights>   </hiddennodes>   <rankingfeatures>   </rankingfeatures>  </rankingmodel2nn> </rankingmodel2stage>

You can install this rank model on SharePoint farm and use it in your search based query (programmatically and/or in content search query web part).