tbh 104C is pretty typical for those 3080 cards but definitely not ideal for longevity. I went through this exact same process with my card last year and the memory junction temps are just brutal on the stock factory stuff. The core contact issue you mentioned is definitely the biggest hurdle when doing a teardown. If you want the best balance between raw thermal performance and compressibility, I usually recommend the Gelid Solutions GP-Ultimate 15W/mK Thermal Pad. These are way more forgiving than the Thermalright Extreme Odyssey 12.8 W/mK Thermal Pad. The Odyssey pads are basically like bricks; if you use 2mm where the card actually needs 1.75mm, your core wont even touch the heatsink properly and your core temps will skyrocket. The Gelid ones are soft enough to squish down and fill those gaps without lifting the cooler off the die. I actually switched my main rig to Kritical Pads 20W/mK High Performance Thermal Pads recently because they sell model-specific kits. If you can find a kit for your specific 3080 brand, it takes all the guesswork out of the thickness measurements which is honestly a lifesaver. A few tips from my experience:

• Use a digital caliper to measure the old pads if they arent too deformed.
• Clean the memory modules thoroughly with 99 percent IPA before applying the new ones.
• Dont forget a high-quality paste for the core like Thermal Grizzly Kryonaut 12.5 W/mK Thermal Grease since you are already opening it up. Basically, the Gelid pads dropped my memory temps from 106C down to about 88C under full load, so they definitely deliver on the hype without being too stiff.

Hey, I've been doing a ton of reading on this because I'm honestly terrified of messing up my own card. If you're really worried about the squishiness factor and core contact, you might want to consider Thermal Grizzly Minus Pad 8 8.0 W/mK. Even though the rating is lower than the ones you listed, they are super soft compared to the stiffer options. For a beginner, having that extra compression is a huge safety net so you don't accidentally lift the cooler off the core. If you want max performance regardless of cost, look at Valor Odin Thermal Pad 15 W/mK. They're top tier but definitely pricier than the others. Personally, I'd stick to the softer ones for peace of mind. Also, a quick tip... grab a cheap digital caliper to measure the old pads. It takes the guesswork out of it so you dont end up with the wrong thickness. Better safe than sorry!

Which specific AIB model of the 3080 are you actually working on? The tolerances for a Strix vs an FTW3 are totally different when it comes to pad hardness. If youre worried about core contact, you might check out Fujipoly Sarcon PG80A 13 W/mK or Frosty Thermal Pad Fugaku 20 W/mK. They have a better shore hardness rating for those tight gaps. Lmk the brand so I can check some data.