If you have lag issues from WeakAuras just Disable WeakAuraOptions once you have the strings set properly and you'll never lag.
This issue (at least the ones i described) has noting to do with WeakAuraOptions, if the main addon has a ~10% memory usage up, with around 3 MB base memory usage that means the addon writes 300 kB data to the memory in each second. And since the the game is very CPU orientated means consuming extra and useless CPU usage can greatly effect frame rates specially in a lower end computers. This is just simply causing FPS drops, but you can reach a level which will overdrive your CPU that much it will no longer going to be able to run the game's code smoothly enough and going to cause lag spikes.
In the past i also raised my concens about this addon, but of course all the WA fanboys denied any of it and tried to protect their precious auras, as well as called me a retard. I also use TellMeWhen and i can see some inefficency on that addon too, specially the addon updates the auras when they are not even visible is a big clusterfuck, but it's nearly not as bad as some issues in Weak Auras.
"Their precious auras" have much less of an impact on performance, considering not all people have 2500 of them..... or even a few hundred. That was the point of this thread, since you missed it.