Would it work for broccoli sprouts?Technically yes, but with some significant caveats:

What could workBroccoli sprouts do contain enough moisture to help initiate fermentation in raw honey, similar to garlic.

The antimicrobial and prebiotic properties of raw honey would be complementary to the sprouts' own nutritional profile. 3

The ACV mother would contribute live bacteria to help drive the ferment.

 Key challengesSmell. Broccoli and its relatives are notorious for producing sulfurous, very unpleasant odors when fermented. One food microbiologist notes that fermenting broccoli straight up produces "possibly the worst smell in the world."

Sprouts are milder, but you should still expect a strong, funky smell.

Texture. Sprouts are extremely delicate. Submerging them in thick honey for days or weeks will likely turn them to mush.

Wrong microbial environment. The ACV mother contains Acetobacter, which produces acetic acid (vinegar). Broccoli sprouts ferment best via lacto-fermentation (lactic acid bacteria in a salt brine), which is a completely different process.

The ACV mother isn't the ideal starter for vegetable fermentation.

Sulforaphane considerations. One of the main reasons people ferment broccoli sprouts is to preserve and enhance sulforaphane — a powerful antioxidant compound. Research shows that lactic acid fermentation can actually boost sulforaphane bioavailability.

Whether a honey/ACV ferment would do the same is unknown and less studied.

The better approach for broccoli sproutsIf your goal is maximum nutrition and gut health, the well-established method is a simple salt brine lacto-fermentation:

Grow or source fresh broccoli sprouts.

Make a brine: ~1 tsp sea salt per cup of filtered water.

Pack sprouts into a clean jar, pour brine over them, keep submerged.

Ferment at room temperature (68–75°F) for 3–5 days, tasting daily. 2

Refrigerate when they reach your desired tanginess.

You can absolutely add raw honey as a flavor note or prebiotic boost to the finished product, or incorporate it into a sauerkraut-style ferment alongside cabbage.

Bottom lineThe honey + ACV mother method is wonderful for garlic, ginger, and woody herbs — things that hold their structure and release moisture slowly. Broccoli sprouts are too delicate for it, and the microbial environment isn't ideal for them. Stick to a salt brine for sprouts — your gut (and your nose) will thank you.

Sources

https://cultured.guru/blog/fermented-broccoli-sprouts

https://thenaturallivingsite.com/preservation/how-to-ferment-broccoli-sprouts-for-maximum-nutrition/

https://hucklebeefarms.com/blogs/healthy-living-with-honey/probiotic-honey-benefits

https://sproutskrautsandspice.wordpress.com/2015/05/01/fermenting-sprouts-really/comment-page-1/