Your Core is high, not the memory - you’re barely doing any OC at all there.
This is insanely inefficient and nothing to do with sillicone lottery. LHR unlock mechanism works better the higher the core, but that doesn’t mean it’s more efficient. The only reason you even see an increase in hashrate is because of LHR, with FHR cards you actually underclock the Core as low as nvidia allows - it’s the LHR unlock making use of core to fool the LHR lock, not your ETH mining per se.
I can get 47 MH/s with core at 1450, which consumes significantly less than what you do. Lock your core at stock (1410Mhz for mine) and test your Memories’ OC limits first. Once you know how much you can up the memories, then you start very slowly upping the Core clock until you find the sweet spot. For me the sweet spot is at 1470Mhz, higher than that and the hash per watt goes down exponentially.
For comparison, with your displayed 145W consumption I can get nearly 50MH/s, but not worth it due to the hash per watt ratio going down and electricity being expensive here. Currently I am at 1470 locked Core and +3800 Mems (linux numbers, would be +1900 in windows), this produces ~48-49MH/s with 130-140W consumption. Adding PL will not help either, as that consumption is required for the core for LHR unlock reasons described above, or worse it can crash your cards/drivers.
PS: your temps are also shit and your cards won’t last long-term with those temps 24/7. 62ºC core temp means close to 80ºC junction/hotspot temp and depending on your model, most likely around 100ºC. While they are built to handle that, they aren’t built or tested to run that 24/7 over a period of months. And assuming it’s also Winter where you live, it’s only going to get worse.
Sorry for all the edits, I previously had core at 1475 but recently lowered to 1470 as it’s the real efficiency sweet spot for my cards.