Are one time vendors supported in SRM ( replicated from ECC backend to SRM)

Dear All,

I have noticed in various past posts that one-time vendors are not supported in SRM.

Is this still the case fo SRM 5.0 and ECC 6 backend set?

Why is it that one time vendors cannot be replicated to SRM?

If we create a one time venor manually in SRM, can we use this vendor in shopping carts/POs?

Thanks