Thanks for your offer. I actually got the green light on the CM 4.4.x Q&A thread.
I read that flashing the CWM for 4.1 would brick your tablet if you had 4.2 installed, so I was worried that flashing 4.2 on top of an existing 4.1 CWM would brick it as well. It turns out it simply removes the CWM entirely. Good times.
Basically what I ended up doing was:
1 - Transfer the latest official TF300T firmware (zip file) onto an SD card.
2 - Start my TF300T with my old (4.1) CWM recovery and select to flash my android with the zip file on the SD card.
3 - The TF300T bootloader stayed unlocked, but the old CWM was gone.
4 - Using ADB: Upload & flash the new CWM Philz Touch
5 - Install/flash the desired custom rom (from within CWM using SD card)
6 - Restore to factory default (from within CWM)
Now I even installed Grimlock's kernel to allow overclocking.
My TF300T has a new life. It is now very much acceptable in terms of speed.