Did someone test any of the ASM2464PD enclosures with a Thunderbolt host (any Intel Mac with Thunderbolt 2 or 3) and get > 10 Gbps?
OWC Express 1M2 says that the US4EXP1M2 can't do > 10 Gbps for Thunderbolt hosts. If that's true then it's because the ASM2464PD doesn't support Thunderbolt transmission (41.25 Gbps) and is limited to USB4 (40 Gbps). Or ASM2464PD does support Thunderbolt transmission and OWC is disabling that for reasons.
If you go back a few pages, you'll see my screenshots of benchmarks with a 2020 Intel iMac. Thunderbolt 3 speeds are just as fast if not faster than the USB4/TB4 speeds.
Aside from some minor issues with the current firmware, ASM2464PD fully supports thunderbolt 3 transmission.
Searching some previous posts, some reports noted issues with Intel Macs such as connecting at x1 at x2 link rate instead of x4:
#1,314 #1,317
Maybe OWC disabled Thunderbolt for those reasons or to make it cheaper? Does it cost more to add the Thunderbolt 41.25 Gbps capability?
The user you're quoting here has a faulty enclosure and he tested it on Apple silicon Macs with USB4 ports, not any Intel ones. The x2 link width issue posted by me and
@masotime is just an anomaly with the most recent firmware. The actual transmission speed remains unaffected, at least with my Gen4 drives.
OWC's enclosure isn't any cheaper than the current ASM2464PD solutions so no, it has nothing to do with the cost. Also, I don't think there are any additional costs involved in adding the thunderbolt 3 support.
Interestingly, OWC's page for US4EXP1M2 was updated from a few hours ago.
Here's an earlier version from google cache:
What it looks like now:
Maybe OWC's implementation of thunderbolt 3 backward compatibility is limited to USB 10GB/s because:
a) they don't want it to exceed Intel's power spec for bus powered thunderbolt at 40GB/s or b) they don't want to cannibalize the sales of their Intel based TB3 solutions that work at 40GB/s.