How about fix Wi-Fi 7 first? MLO is critically flawed, 320mhz 6ghz channel support is non-existent. Older devices either won't connect or connect intermittently.
I took out my Wi-Fi 7 and went back to 6E. Connected on 6ghz I get upwards to 1.4ghz reliably and my old ooma actually connects.
Between Wi-Fi 7 and 6E, 6E wins every time on speed.
What Router / Access Point were you using?
From my experience, WiFi 7 is still faster on the 6GHz band than WiFi 6E, but you need a proper Aruba/Ruckus or a well configured UniFi AP, if you're using a router from Asus or Netgear, stuff like MLO just doesn't work properly.
In my case, I had an Asus GT-BE98, PS5 Pro supports MLO, but with the Asus router, it would just always sit on the very slow 2.4GHz band, for no reason at all, it just would.
UniFi U7 Pro XGS though, connects to both 5GHz and 6GHz simultaneously.
Also remember, for WiFi 7, 6GHz and MLO to work, WPA3 is required, you can't use WPA2 with optional PMF, limiting old clients (Nintendo Switch for example) from connecting, I just create a second SSID for them and forgo all the new tech as they can't utilise it anyway.