@Dave_McLaughlin is correct.
And I’m also refering to this :
Yes we did talk about this (16Bit SPI Mode - #11 by Gus_Issa) and I still think that this is something that should be present in SPI. (I would even say that I don’t understand why you did it at bit level).
And this is really simple to implement at firmware level as it is only a matter of register setting.