WE FINALLY HAVE EFFICIENCY NUMBERS! Yes!
In terms of absolute values, the P31 is lower but the P41 is superior for performance per watt.
Relevant quote
"Those wanting to see how the Platinum P41 fares with power efficiency do not have to look any further. Not only does it beat the other PCIe 4.0 drives, it even exceeds the class-leading numbers put up by the Gold P31. The Gold P31 does have lower peak and average power draw, but the Platinum P41 can finish tasks far faster. The Gold P31 also has lower idle power consumption with ASPM/LPM disabled.
Testing power efficiency with more-nuanced tests might produce different results, but many users buy PCIe 4.0 drives for the raw bandwidth. Consumer workloads are generally pretty light and quick, with lots of idle time. Therefore, the value of power efficiency for an SSD is questionable past a certain point; however, we can get some idea with a quick copy test like this. The Platinum P41 is simply the most efficient of the high-end PCIe 4.0 drives to date.
The Platinum P41’s S.M.A.R.T. report shows two throttle points, at 86C for throttle and 87C for critical. In practice, we saw throttling around the 84-86C range as measured by the sensor, which corresponded to a 70-72C range for the NAND. During a write workload, we recorded the surface temperature at about 85C versus 82C reported by the sensor, so reports of the drive throttling by 90C, on FLIR, are accurate. We were able to find some relatively graceful throttling after writing about 420GB.
Consumer NAND flash is usually rated for a 0-70C operating range - the idea that NAND works better at higher temperatures must be taken within context. We do recommend that users equip this drive with a heatsink, if possible. This is especially true if you expect the drive to dwell in a warmer environment."
Small heatsink sounds like it would be perfect and keep drive temps well in check, especially in a thermally constrained environment like a laptop.