The "Oval" ring system is not the "Quick Cuff" system, it's the QCS Oval system made for the Antares dry glove system. I would have strongly advised to measure the outer diameter of the P/U rings, then turning the sleeves inside out and measuring the sleeve diameter, and marking them up at the best fit location, prior to cutting the sleeves on the suit. The "best fit" location is a point at where the diameter of the sleeve is 0.5cm smaller than the diameter of the P/U ring. This creates a very snug fit for the P/U ring inside the sleeve when mounted. I also would have advised to take that time before cutting to measure the length of the sleeves to ensure they were exactly the same length on both sides when marking them up. This way, when you cut them, they end up exactly the same length and the same diameter with a snug fit for mounting the P/U rings. I would say you got VERY lucky after blindly cutting the sleeves based on an assumed fit. Next, heavily sanding the P/U rings is a must, absolutely (and honestly, this is exactly where a dremel tool shines), but there's no need to sand the trilaminate material of the suit (or the neoprene if the suit is neoprene). Glue will seep into the cloth material and form a permanent bond with the first layer. You should allow that first layer on both the suit sleeves and the rings a full 24 hours to cure completely before applying the second. Use old wine bottles for the sleeves to keep them sitting upright while they dry, so they don't touch anything. If you apply glue too quickly, and don't give it time to cure completely before applying the second layer, typically this results in brittle glue with a partial connection, and it doesn't last long. It either delaminates or becomes brittle and begins breaking down. This is often the reason why some people have neck or wrist rings that come off their suit after a single season or within a short period of time. Whoever put them on the suit (either at the manufacturer or a local tech) didn't use the correct type of glue, or didn't do proper prep work (such as correct sanding), or didn't give the glue time to cure properly before moving on to the next step.
The "Oval" ring system is not the "Quick Cuff" system, it's the QCS Oval system made for the Antares dry glove system. I would have strongly advised to measure the outer diameter of the P/U rings, then turning the sleeves inside out and measuring the sleeve diameter, and marking them up at the best fit location, prior to cutting the sleeves on the suit. The "best fit" location is a point at where the diameter of the sleeve is 0.5cm smaller than the diameter of the P/U ring. This creates a very snug fit for the P/U ring inside the sleeve when mounted. I also would have advised to take that time before cutting to measure the length of the sleeves to ensure they were exactly the same length on both sides when marking them up. This way, when you cut them, they end up exactly the same length and the same diameter with a snug fit for mounting the P/U rings. I would say you got VERY lucky after blindly cutting the sleeves based on an assumed fit. Next, heavily sanding the P/U rings is a must, absolutely (and honestly, this is exactly where a dremel tool shines), but there's no need to sand the trilaminate material of the suit (or the neoprene if the suit is neoprene). Glue will seep into the cloth material and form a permanent bond with the first layer. You should allow that first layer on both the suit sleeves and the rings a full 24 hours to cure completely before applying the second. Use old wine bottles for the sleeves to keep them sitting upright while they dry, so they don't touch anything. If you apply glue too quickly, and don't give it time to cure completely before applying the second layer, typically this results in brittle glue with a partial connection, and it doesn't last long. It either delaminates or becomes brittle and begins breaking down. This is often the reason why some people have neck or wrist rings that come off their suit after a single season or within a short period of time. Whoever put them on the suit (either at the manufacturer or a local tech) didn't use the correct type of glue, or didn't do proper prep work (such as correct sanding), or didn't give the glue time to cure properly before moving on to the next step.
Thank you for the detailed feedback!