Maximum number of DL layers UE support

Hello All,
Can anyone explain why 3GPP 36.306 say max no of DL layers UE support is 8, as seen Category 14?

Per UE is 8, per cell in NR could be 16.

I think cat 14 & 17 are not commercial UEs.
3gpp say cat 14,17 can support 8 DL layer.
But commercial UE do not support 8.

In caccombos are only commercial UEs.

If it is not there, yet, it doesn’t mean it will not come in the future.

In cacombos we can see just 11, 12, 13, 15, 16, 18, 19, 20.

Yes because those are commercial UEs.
There are no commercial UEs with 8 layers, not yet in cacombos.
But Huawei has CPE with 8 layers in DL.

If Huawei CPE with 8 layers is not in cacombos it doesn’t mean that it does no exist. It is simply not yet in cacombos.

Here it is even from Oct 2019:

Do you think CPE/TUE of huawei can work with other vendor BTS well?

Every UE has specs to cover like 36.101.
Cannot be released in any market without passing those tests.