Does Mac Studio M2 Max support USB 3.2 Gen 2×2

Not to the best of my knowledge.

There have been reports that when you connect USB 3.2 Gen 2x2 SSDs to some other Apple Silicon Macs (not this particular one), the speed you get is consistent with USB 3.1 Gen 2 ("up to 10 Gbps").

According to Wikipedia's article on USB4,

• USB4 defines a new "up to 20 Gbps" transfer mode that is incompatible with USB 3.2 Gen 2x2 (even though it has the same nominal speed). This mode is mandatory for USB4 host ports.
• USB 3.2 Gen 2x2 is optional for USB4 host ports.

To top it off, Apple's Technical Specifications don't mention support for USB 3.2 Gen 2x2 – only for USB 3.1 Gen 2. One would think Apple would mention USB 3.2 Gen 2x2 if they did support it.

All silicon Macs have an issue with USB 3.0 speeds. They are about 20% lower than with Intel Macs. If you want Max speed stick with using a TB port/drive. All SSD's should be formatted to APFS.

The FRONT ports on the Mac Studio Max are SPECIFIED as supporting up to 10 G Bits/sec. That is NOT 2x2 speeds.

The back ports can support up to 40 G bits/sec speeds.

The back ports can support up to 40 Gbps speeds, but that is for Thunderbolt 4 and USB 40 Gbps modes - which don’t help if the device you are plugging in wants to speak USB 3.2 Gen 2x2.

AFAIK, the standard imposes no requirement to implement the optional “up to 20 Gbps” USB 3.2 Gen 2x2 mode, even when a port supports other, faster ones.