Another update!
Tires ended up needing to be replaced (I believe they were Continentals if memory served). Not many options for the 265/45R21 but my guy recommended the Michelin Latitude Tour HP and they are a really nice upgrade from what the ride/feel was before.
Had to replace the amp that sent the signal from the fuel tank to the CPU (was honestly just annoying, nothing to write home about other than it wouldn't pass inspection otherwise.
And today, finally got around to tuning with the Uprev. Wow! What a difference from a responsiveness perspective. 1500-3000rpm's are a completely different feel and the car just wants to speed up and speed up fast. Was a bit nervous that I wouldn't notice that much of a difference but it truly is. Now it's tuned for 93-octane and the redline was pushed up to 7700rpm. You can feel the difference all over, really. I'll have a video to post of the dyno (soon) but I have the readout for you all to see. $1,000 isn't cheap, but keeping this car long-term I can already tell it's gonna be a great investment. Until next time!