Modding Magic Sites questions

[Hoplosternum]

Is there any way to make a new magic site which has say a Conjuration bonus? I can't see any command in the Modding pdf for this. Nor can I see any copysite command and/or clear features from a site commands which would let me copy existing sites and then use them.

Assuming there are no such commands is it possible to ammend existing magic sites? For example if I wanted a Conjuration 20% bonus site is there anything I can do with say site 408 Wolven Gate which gives this bonus? And if so how can I handle the fact that it already has one other feature (1N in this case) and can that be changed?

Can I even change anything about existing sites? For example can I make them none unique by adding (say):

#selectsite 408
#rarity 0
#end

To change Wolven Gate from a rare site to a common one? Or would this cause it to lose it's gem and conjuration bonus?

I have read through the magicsite mod but cannot see anything that is obviously adding bonuses or copy and modifying existing sites. So I am guessing it's not possible to get these affects on new sites?

Thanks!