What type of ECC is a requirement? All DDR5 has on-die ECC but it's hard to get real ECC with error reporting. Since errors are pretty rare (about 1 / year per 100GB) and you sacrifice to get it, seems like a hard choice.
True DDR5 ECC memory exists, and is not hard to find—just look for “server” RAM.
the laptops see two unexplainable crashes per 6 mo.