A couple things of note from my recent road trip from NJ to Kansas City. (I think I spent more on tolls than gas, and even that was under $10)

Giant-PA points can also be used at Martin's. I couldn't find it having been mentioned previously. I made a Martin's account and entered my existing Giant-PA Bonus card number and it linked the points.. Possibly was an unnecessary step.

Even though the FR app indicates otherwise, S&S and Giant-MD points worked in Kansas City and St Louis. I reckon that most anywhere in Hy-Vee country that shows at full price in the FR app will actually work.

Though they aren't as generous with giving them out, Hy-Vee points can be stacked in FR with Giant/S&S to get a discount over $3. Right now, this would only really matter for someone who was taking i-80 all the way through to Sacramento or the Bay Area where gas prices are almost $4. Everywhere else with $3+ gas is in Kroger Country. At $0.20 discount per $100 spent on retailer GCs (current offer, maybe they have better at times) not the greatest return, but I bought a couple Happy Cards to test it out. Looks like that route may be getting harder soon anyway,