I have thought about this off and on since first reading WoK. On my current re-read I ran across them again and did a search here in the forum but found no reference to any theories on them. I also looked in the Wiki, but did not find any hints to indicate some have found ways to access hidden power in them.
Is it possible that glyphwards are just missing some component that would release a more perceptible effect? We know that glyphwards are prayers to the Almighty, but never see a manifestation of that power.
We read of glyphs on the Honorblades and Shardblades, on weapons the Parshendi have access to, and on the Knights Radiant shardplate. It is my theory that glyphs were a way to access or focus Stormlight in the past and has since been lost. My hope is that in Words of Radiance we will see this lost art regained. Though I know there are plenty of books to come where this could be covered.
In truth, part of this came to mind because Shallan mentioned in her interview with Jasnah that her glyphwards are regarded as quite impressive and the fact that she can now infuse, or at least access stormlight. Perhaps Shallan will find a way to use them together to create new alternatives to fabrials.
Any thoughts, ideas, or holes where this just can't be possible?