"Wherever I may roam ..."
1. open text
2. insert the name of the genius loci where appropriate
3. shake well
4. collect dakṣiṇā (ok, this is not very nice of me)
4. you're done!
It never ceases to amaze me how flexible Vajrayāna is. I am sure that there have been many texts of this type, basic blueprints for the incorporation of local deities creating an ever expanding corpus of rituals. The praise verses are not entirely devoid of poetic merit either.
Apart from the evident case of locals seeking the appeasement or propitiation of their local tutelary god via the tantric religious specialist, there is another instance for the presumable usage of this work which springs to one's mind. This is the ritual for 'requesting the territory' (bhūmiyācanā and synonyms) in maṇḍala-initiation. As you may remember from the Vimalaprabhā and other more comprehensive works, the officiant needs to gain permission for using a particular piece of ground in the rite from both temporary rulers (the king, etc.) and supra-mundane rulers (genius loci, etc.). It is only then that he may proceed to build the maṇḍala.
This Mongolian ms. comes from my private collection. Please acknowledge the source if you are going to use it.