depending on how magic propagates, we might just be able to make something like Nikola Tesla's wireless energy transmitter. cause then we might be able to power runes with a energy receiver, instead of what ever we're using now. this would allow a whole lot more miniaturization, as well as reducing individual rune upkeep.
as for power, it really depends on how runes are powered. if they just draw in ambient magic, theres not much use for it. If it runs off of crystals or smth, thats different. I would be cool to see if we could replicate the hearts love/joy/friendship to power converter, but with how complicated that thing is, it may just be easier to just use it as an idea of what is possible with the right runes.
I would theory craft somemore, but I'm not too solid on how magic or runes work. Now, if someone where to give a reasonable idea of the basics, im bored and willing to design a runic circuit lol.