Hello.
@Egon and @Stormblood you talked about not mixing mantras because it was stated in the Full Chakra Meditation page.
The exact words are these:
There are different words of power that you can choose from to empower your chakras. Make sure you stay consistent, for example, if you are using Rune vibrations, then stay with the Rune vibrations for the entire session, using the Rune vibrations for all seven chakras.
The words of power are given in levels. The "Traditional" vibrations still do work, but they have been corrupted and drastically watered down. The reason I am leaving them here is that the correct vibrations in Sanskrit can be overwhelming if one's soul is not yet strong enough to handle the energy. The words from the 1586 Necronomicon, along with the traditional words of power can be used by new/inexperienced people. The Runic vibrations came directly from both Satan and Lilith, as I used these under their direct supervision in working on empowering a human soul in spirit form who has passed form this earth and is now residing in Hell.
HP Pythia does mention "to empower your chakras," and it's truly the only place it mentions not to mix them up. I believe the reason it's important not to mix them up in the full chakra meditation is because Sanskrit may work more powerfully to someone than runes, and so it would be unbalanced to use the first for one chakra and the second for another chakra.
@Aquarius, I have also done my own workings with combining mantras (I've used the shortcut meditation from HP Pythia) with Satanas, Aum Guruavay and runes.
As you said, the full chakra meditation by Astarte also uses a combination of mantras/ runes (sun mantra and Algiz).
I like combining them because we can cover many uses like this.