Option key not working after liquid damage. Keyboard or logic board?

I made the gut-wrenching mistake of spilling a half glass of water on my mid-2014 MacBook Pro. I immediately turned it over, it made some sizzling noises, and then turned itself off. To be more specific on location, it was the top left of the upper case, activating the liquid sensor by the power and the fan nearest the power.

Over the next 40 hours or so, I had a fan blowing on it, and set it in a bag of rice for a good 12-18 hours attempting to dry up any remaining moisture. It turned on perfectly after that, I was able to make a backup and start searching for issues. The only thing that I can find is that the left option key is registering as control+option. Calls to the Apple Store and authorized Apple repair shops are coming up with estimates of $600-$1,240.

I've made a couple tricky repairs on MacBooks and iPhones in the past so I actually somewhat enjoy doing hardware repairs and want to attempt to repair it myself. My question is, will just replacing the keyboard remedy my issue? Or is this input error related to an issue with the logic board?

I've read some things to make sure I clean up the corroded areas on the logic board with isopropyl alcohol as well and plan to do that. Anything else I should be aware of that could affect it long term?

Apologies if this has been answered already. Spent quite a bit of time researching these forums and others to try to find a specific answer, but came up short. Thanks in advance for your help!