RomRaider

to help this along, the 2011 WRX ecu id I'm dealing with is 7412587007. The 11 STi is well defined, with a ecu id 7412597007.

Would it be safe to assume the address locations would be the same? Can I simply copy and paste the logger def for the 11 STi FBKC and enter in the 11 WRX ecu id?

No the STi addresses will not work with the WRX.
Why not just upgrade the WRX ROM and use this def set.
viewtopic.php?f=34&t=7519

Awesome, didn't know i could do that to be honest. I have "upgraded" roms before, but I honestly don't know the convention for doing so. How do you know what you can update to?

I have updated from say A4SGC00C >A4SGC10C, but it seems like I've tried to update from A4SGC00C to A4TC401L (just another example, it might have been different) and failed. I wish I could get some guidance on this.

Either way, thanks a bunch. I have been meaning to contribute to these def efforts. I'm going to have to financially as I'm spending a lot of my time tuning. I figure I should be cutting you guys in on that profit since without this effort I wouldn't be tuning...

Updates are a bit tricky to figure out. The best source is Subaru when they perform a "campaign" update.
You should be able to go from A4SGC00C > A4SGE01C but not to A4TC401L as this is for a different year and specific to a transmission type.