I dont really think there are too many ‘universal’ enhancers. This is because most of the molecules have secondary properties that will also modify the results of a mix and usually need to be adjusted for.
A few examples, Hedione which is man made was tried as a universal enhancer and failed because what works well with one mix doesnt mean it works identically well with every mix if it has other properties. In the studies below, it turns out that it enhances diffusion but also hits like Androstadienone or EST, increases cooperation, releases sex hormones etc so its certainly a great addon but its going to buffer and cause mixes to behave much differently… Just needs to be in the right mix instead of every mix. Tuth + TAC benefitted from added hedione for example. Since its in popular colognes like Acqua Di Gio thats another reason why people have different experiences when adding to pheromones.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5411439/ - new one
https://pheromonetalk.com/t/the-smelling-of-hedione-results-in-sex-differentiated-human-brain-activity/64501
ISO E Super increases both diffusion distance and longevity and taken alone that sounded universal. For specific purpose like getting a mix with a too heavy molecule like Oxytocin or Astaxanthin in the air its wonderful and has a pleasant scent women love. But it does also buffer like a social so you need to keep that in mind. It also is going to slow down diffusion which can lead to longer times to start working.
Some molecules do well with many mixes, , P86 with its attraction at a distance, beautification, memory imprint/crush, touching/velcro but also buffers. P96 fixes bad mixes and fills in the gap, but also has emotion imprint, comfort and bonding among many other things. P79 amplifies many of the pheromones in mixes, but seems to work best for me in blends with mood enhancers or negative is amplified …