As for ECC memory support, this is a really relevant question, because formally the Zen4 Phoenix series, for the first time in x86 history, supports 256GB of RAM (but now the maximum available at retail is 32+32, ddr5 5600 modules for 64 and 128GB are not on sale yet).
With RAM amounts of 32GB+, especially on the business series, there simply must be support for ECC memory for a trivial reason - if the laptop is constantly used in sleep mode, because. hibernation is very slow in terms of write speed of this size of memory even on a pci-e 4.0 x4 SSD, and in sleep mode S3 (STR) - which the bastard hardware manufacturers deliberately removed in collusion with M$, it falls asleep in 1-2 seconds and wakes up in 1 -2 sec maximum. Feel the difference if you need to put a laptop connected to a power supply to sleep 5-10 times a day... with hibernation you will lose up to 0.5 TB of SSD resource per day with loaded software and a cache of 50-60 GB of RAM, and recording and recovery will be extremely slow.
The greater the capacity of the RAM, the more strongly it is affected by any interference and fluctuations in the electromagnetic global environment on the planet. Therefore, error control in the form of ECC is already very important, especially in business-critical applications.
The new-fangled filthy S5(S0), conceived by the scoundrels in M$ as a spying mode for Windows users with wi-fi, cable Ethernet and much more, even working coolers, has nothing in common with the good old S3(STR) - ideal sleep mode, where only RAM works (in slow update mode) and of course a unit for spying on all x86 owners since 2006 in the form of an Intel ME hardware module. Which is impossible for the average person to disable using simple methods - remember, the NSA can always connect to your machine. even if the power is turned off, but power is supplied from the battery, and even more so from the power supply.
No one will hibernate 256GB of RAM - it's simply too long even on a pci-e 5.0 x4 SSD - it will take more than 30 seconds to save and restore from disk. This means that laptops should then sleep well in a mode like S3 (STR) and wake up quickly in 1-2 seconds, but with RAM that can check errors in itself on the fly.