There is exactly one Z690 board that has nearly all of the features I looked for - ASRock's
Z690 Aqua OC, currently selling for US$890.
My list:
- Overclocking features in BIOS, with strong power delivery and post-code readout
- 10Gbit LAN with a backup NIC (usually 2.5Gbit)
- at least four M.2 NVMe slots that do not hamper PCIe connectivity (the Aqua has three)
- Two DIMM slots for memory overclocking
- Thunderbolt 4 on rear I/O
- Clear CMOS and BIOS flashback on rear I/O
- Onboard power and reset buttons
- Two USB 3.0 type-A headers for four USB type-A ports up front
- Dual BIOS (Aqua lacks)
- ATX instead of EATX
What I find frustrating is that board makers seem to dance around this list. Instead, there's a focus on bling, ludicrous power delivery, and weird PCIe lane and slot configurations. And this regardless of how much you're willing to spend on a board.