Why don't you want to reallocate from the Magnet? That seems the best and easy thing to do, and can always be moved back if needed.
Or you can spend over the CL, and simply make an online payment to bring it back down under.
Depending on how much you can spend in 3 months, it shouldn't be that difficult to meet $2K in that period. Spending $250 a week would be sufficient, and be achieved well under the deadline.
Also, by putting that much over spend on the card, it could show them how much you need a higher CL.
Let me know if you pull the trigger on the SPG and your SL, if you that's cool.
Just an update — I just pulled the trigger. They gave me an odd 14.5K limit. HOWEVER, they took it away from my Delta, which is now sitting at $15K, down from the 25K. They did this without notice. I just noticed that my Delta card has been reduced. Not really mad, as I was planning on transferring limit anyway.