Changing Mythic Europe now has bits about warping the environment. Might I suggest that warping is getting a bit out of hand. It's starting to resemble Chaos from 40K. Might I suggest a list of things that cannot be warped.
Items created with magic from the Realm causing warping. Create a tower with CrTe and it (like creature with a might score) doesn't take warping.
Items from the realm causing the warping. A spoon from the magic realm cannot be warped by magic.
Meteoric iron cannot be affected by magic (including being warped). Doing so would violate the limit of the lunar sphere.
Symbols of the Divine.
Warping has been around since the beginning. Warping the environment is a consequence of constantly controlling it or using high level spells to shape/manage it on a frequent basis. I honestly haven't heavily reviewed the book heavily and what it says about it, as I just acquired it a few weeks ago. But, Conjuring the Mystic Tower should have a warping point, why is that a problem?
Your interpretation of chaos is really mundane. Warping is not malevolent, nor actively seeking to corrupt. It isn't even necessarily negative. It's more like thaumic radiation essentially.
Or as my character in my saga would put it, it's the result of having the gears of the universe that define your life being tweaked a bit too much.
It's been like that from the start. Heck, I think Ars Magica had the idea of "Auras" and "Regios" before Games Workshop came out with "Realms of Chaos"..... Mythic Europe has been spiritually morphic since first edition, and the use of "power", of whatever realm, to create such, has always been part of canon.
I quite like the idea of magic warping the environment. It isn't a new one but it is something that tends to get overlooked. I wrote a section in Transforming Mythic Europe that dealt with that kind of warping and it was interesting (in the writing at least) to treat the place just as you would treat an individual and let it accrue Flaws. Then of course you have to determine how those Flaws (or their mechanical effects) affect those who live within those places.
You certainly don't have to track that level of warping for each location. You could even hand-wave it all away and just not use it or you could decide that a place with an aura cannot warp, which takes care of covenants and the like. But I do think it's nice to have the option.
I think Michael Moorcock is largely the origin of this sort of idea in modern Fantasy/RPG. Certainly, Games Workshop is/was fairly open that he is their inspiration.
And Moorcock was presumably influenced by the various real-world myths that have some kind of realm of formless chaos (which often existed prior to the world).
What I don't like is that spells for magical heating and light would now cause the environment to take two warping points a year. Eventually, thats going to make a room or structure unusable. The environment ends up picking up things like poie eyesight, giving you a constant mist. Also, a building can be warped just by being in a powerful aura. Over a 70 year saga that can be a lot of warping points. It seems more like an excuse to have a bookcase eat the library than anything else.
If warping of items is going to be a problem, what about items directly from the magic realm!
I've personally ignored warping from the aura for inanimate objects. And Durenmar is a good example of not doing this, what with their Aura of 7 and being the premier library of the Order, I don't think it should happen.
Generally, while objects can become warped, in any saga I run, and as far as I can tell, in the one I am presently participating, rooms don't get warped from their local aura, and only the object the magic is directly affecting gets warped by things such as magical lighting.