ECC RAM on a consumer Intel board is a no-go

No.

Intel reserves ECC memory support for their Xeon processors and workstation chipsets (like W680). On a consumer Z690 board with a Core i5/i7/i9, the memory controller simply ignores the ECC bits. You can physically install ECC RAM, and the system might even boot, but you get zero error correction — just slower, more expensive memory.

AMD is a different story. Ryzen (non-APU) on most B550/X570 boards supports ECC if the motherboard manufacturer enables it. But on Intel, unless you’re on a Xeon platform, it’s a dead end.

Don’t waste the money. Buy standard DDR4 or DDR5 for your Z690 build.