You say that in women who've had faux phalluses constructed from skin taken from their arms:

Production of precum is anecdotal but possible due to the skene’s glands/prostate in their bodies.

This suggests you think male "precum" is produced by the prostate, the male counterpart of the female Skene's gland. Not true. Male "precum" is produced by the male bulbourethral or Cowper's glands and Glands of Littre that are located at the base of penis and open up to the male urethra.

Cowper's glands and the Glands of Littre are entirely different to the prostate gland. Their female counterparts are the Bartholin glands, which are located on either side of the vaginal opening.

Also, male "precum" is a constituent part of male seminal fluid. Scientists have shown that in a majority of cases, the preliminary form of seminal fluid produced prior to ejaculation that you call "precum" - a term that medical professionals and sex educators eschew and warn against using - contains viable, motile sperm. No secretions made by a female body contain sperm, not even trace amounts or weak forms of sperm.

Moreover, all male ejaculate - "precum" and full-fledged seminal fluid - travels through and comes out the urethra, located inside the penis. And one of the functions of male "pre-cum" is to neutralize acidity created by urine in the male urethra so as to clear the way, and make a more hospitable environment, for the passage of sperm. Whereas in females, the urethra is entirely separate to the vagina. Yes, the vagina is normally relatively acidic, but that's due to the special flora of the vagina dominated by Lactobacillus. It's not because urine comes from and gets left inside the vagina as routinely happens with the penis due to the nature of male anatomy.

In any event, the fluid males produce known in imprecise parlance as "precum" is not the same as the vaginal secretions that come from the female Bartholins glands or the Skene's gland. The secretions produced by these female glands have been shown to contain a number of components also found in or similar to male pre-ejaculate and full-fledged seminal fluid, but the female secretions have also been found to be different in many ways.

For example, female vaginal secretions have been shown to have all sorts of immunological and antimicrobial properties. Though the female Skene's glands secretions are produced upon sexual arousal, even they apparently do more than provide lubrication that from an evolutionary POV probably developed to make PIV het sex easier and more pleasurable for females, thus providing het females with an incentive to engage in PIV sex more, leading to more reproduction of the human being - the goal of all species.

The fluid produced by female Skene's glands also contains distinct antimicrobial compounds and such elements as zinc that apparently are not found in any male secretions. This has led some scientists to speculate that one of the reasons female humans evolved to produce this fluid is because it protects us from infection, particularly UTIs/cystitis associated with or triggered by PIV sex.