lovely top but whatta beater otherwise.  not sure what to make of the price.  looks like the electronics have been modded,. hopefully with factory stuff...

https://reverb.com/item/58489120-alembic-essence-quilt-top

Electronics look legit.
No doubt.

Not too sure about the provenance of the added circuitry, though. Or the side-mounted jack.

The added stacked pot is 100% NOT legit as we don't buy any stacked pots. I can't tell you anything about what was added, but a big hint about modifications is any sign of electrical tape is a clue it wasn't done here.

If you aren't demoing the bass in person to test to your satisfaction, I would ask the seller about the mods before purchasing this bass.

I didn't think the stack pot was original. The knobs appear to be EMG, so maybe someone integrated one of their BT circuits into this bass?

Very much looks to be an added EMG BT circuit. I wouldn't pay extra for this privilege.