In 2024 I would suggest deploying 2x25G instead, via e.g. MCX4121. Pricing is similar (<$30 NICs), but:

* 2x25G throughput is higher than 40G,

* 25G latency is lower than 40G,

* you can use 25G ports as 10G ports, and

* you can use DACs to connect 4x25G <=> 100G

That last point is particularly relevant given the existence of switches like the Mikrotik CRS504, providing 4x100G ports on 25W.