In DM the Tleilaxu create an artificial analogue to The Agony. The Tleilaxu agony awakens the ghola to his previous (serial) memories into the equivalent of a RM, but for only his own previous incarnations rather than for his entire genetic bloodline. For the purposes of a ghola we might suppose that he has no genetic bloodline since the Tleilaxu would have effectively rubbed that out once they modified a person's genes and cut him off from his heritage.
The Tleilaxu also created their own KH in their desire to find a way to thwart Paul, but we don't really know exactly what this means in terms of the properties of that KH. We expect he had both male and female OM, and I don't see how he could avoid being prescient and maybe even a mentat to be a real KH that the Tleilaxu could use as a blueprint to study Paul remotely. If he had lacked any of these things I wonder whether he would have been of any use to them in learning about Paul. But even so, this was not 'their version' of a KH; it sounded more like they just churned up a copy of the BG KH (or they managed to clone Paul, who knows).
But what of the gholas as Tleilaxu analogue for a BG RM? The RM is, in a way, incomplete, and the full potential of a RM is realized in the KH. In keeping with my analogy, what, then, is the completely realized version of a ghola? Here is a quote from CoD that may shed some light:
Children of Dune wrote:The life of a single human, as the life of a family or an entire people,
persists as memory. My people must come to see this as part of their maturing
process. They are people as organism, and in this persistent memory they store
more and more experiences in a subliminal reservoir. Humankind hopes to call
upon this material if it is needed for a changing universe. But much that is
stored can be lost in that chance play of accident which we call "fate." Much
may not be integrated into evolutionary relationships, and thus may not be
evaluated and keyed into activity by those ongoing environmental changes which
inflict themselves upon flesh. The species can forget! This is the special value
of the Kwisatz Haderach which the Bene Gesserits never suspected: the Kwisatz
Haderach cannot forget.
-The Book of Leto, After Harq al-Ada
If the KH has the ability to see that which is lost to history, to know the things about the past which otherwise would have been gone due to lost bloodlines and disappeared peoples, then he would be one who knows things that it doesn't make any logical sense for him to know in a linear sense, almost like magic. This may well be suggested throughout the series, as prescience and the powers of the KH are often expressed as defying understood logic and linear causation; causation itself is all but denied in general in various passages.
There have been a lot of question marks about what the final incarnation of Duncan really is, and how he could have recovered his serial memories even of the Duncans that were lost and their genes not recovered. What if he is the Tleilaxu equivalent of the KH? Not actually a KH, but to a KH what a ghola is to a RM, by analogy? Maybe the Tleilaxu found the way, genetically, to achieve a 'filling in' of missing knowledge in their ghola's memories just as the KH can mysteriously fill in the gaps in human knowledge. Might this also imply that the Tleilaxu found a way to create their own version of prescience, just as naturally born humans occasionally had the ability? We wonder how Duncan could have visions of the old couple, for instance, or how he saw the Net.
Then again, we have some hint in DM that Hayt possessed something like the capability of prescience, although perhaps it hadn't been unlocked in him fully. Maybe this innate potential for prescience, coupled with recovery of serial memories, would be enough to allow him to bridge space and time like the KH did, only in a different way. Recall that Marty & Daniel refer to Duncan as being spread thin, as the RM's are, and that this fact allowed them to have glimmers of M&D. In the case of the RM's it was only a mere shadowy hint of something, of being watched, but in Duncan's case he had something in him more than merely being spread thin (i.e. having a long line of memories). Maybe it was the same thing allowing him to see his own lost memories that allowed him to see M&D and the Net clearly - that KH-like trait that allowed him to fill in missing data seemingly 'from nowhere'.
If I'm right then it would mean that Duncan really is the culmination of the Tleilaxu's attempts to create technologically artificial ways of achieving similar things to what the BG had to achieve through breeding and drugs. It would imply that Duncan is the Tleilaxu KH, although I'd like to state clearly that I don't mean by this to say his is a 'better' KH or 'super-KH' in any sense of being more powerful, like KJA and Brian wrote; just a different kind of KH.